Hello everyone,
I am thinking of teaching a graduate level course on SPSS. I'm imagining that it would assume no background with SPSS, but with bring students to a relatively high level of sophistication. The course would focus on simple statistical techniques so that this is a course about SPSS, not about statistics. Does anyone have assignments and lectures they'd be willing to share? What about textbook recommendations? Thanks! Kim Barchard Assistant Professor University of Nevada, Las Vegas |
Kim,
I think that is an excellent idea. From time to time and when we can find them (and have the money to pay them), we have hired grad students to work on data management and analysis projects. I've noticed that their spss skills are pretty limited because they learned just enough of spss to get through a statistics lab. It sounds like you have something else in mind. I would assume that your students will have had a research design class(es) so that they will understand different designs and that they have had a (several) statistics class so that they understand how to conduct and interpret different statistical tests. Your class might fit into that area between design and statistics--an area I'd call 'data management and preparation'. I think your syllabus is every non-statistics command in the syntax reference plus the nonsyntax manual documented features. I would probably skip macros, the matrix command set, scripts and Python--unless there is time to include them, and then, I'd do in the order listed. In addition, they need an understanding of how to setup data for different statisical procedures. Lastly, they need to know how to make spss output connect with other programs, especially word, excel and powerpoint. I'd say that to start with there are two required 'texts'. The syntax manual and Ray Levesque's book, which you can get from the spss website. If you go into scripts and Python, I don't know what documentation is available as there is nothing--as far as I can see--in the manuals directory. Maybe somebody else can say. Gene Maguin |
I replied to Kim privately with an attachment but want to give one more
voice to the importance of Gene's comments. I see very few stats teachers going much deeper into SPSS that how to use the drop-down menus, leaving students with a very simplistic view of data analysis. SPSS is NOT a spread sheet. Students need to learn early on that SPSS is not just another expensive calculator. It's a tool for solving problems. For instance, it may take a student several finger-numbing mouse clicks to recreate contrast codes created, but messed up, in the previous day's work. Or he/she can simply open, edit, and run the syntax written the day before (not very sophisticated but it's a start): **COMPARE A1,B1 TO A2,B1 COMPUTE dummyc_1 = 0. DO IF (orglevel = 1 & gender = 1) . RECODE dummyc_1 (0=1) . END IF . DO IF (orglevel = 1 & gender = 2) . RECODE dummyc_1 (0=-1) . END IF . EXECUTE . We are very good at teaching students how to generate numbers. We could do so much more to help them learn how to solve data problems. For what it's worth. *************************************************************************************************************************************************************** Mark A. Davenport Ph.D. Senior Research Analyst Office of Institutional Research The University of North Carolina at Greensboro 336.256.0395 [hidden email] 'An approximate answer to the right question is worth a good deal more than an exact answer to an approximate question.' --a paraphrase of J. W. Tukey (1962) Gene Maguin <[hidden email]> Sent by: "SPSSX(r) Discussion" <[hidden email]> 01/12/2007 11:30 AM Please respond to Gene Maguin <[hidden email]> To [hidden email] cc Subject Re: Graduate course on SPSS Kim, I think that is an excellent idea. From time to time and when we can find them (and have the money to pay them), we have hired grad students to work on data management and analysis projects. I've noticed that their spss skills are pretty limited because they learned just enough of spss to get through a statistics lab. It sounds like you have something else in mind. I would assume that your students will have had a research design class(es) so that they will understand different designs and that they have had a (several) statistics class so that they understand how to conduct and interpret different statistical tests. Your class might fit into that area between design and statistics--an area I'd call 'data management and preparation'. I think your syllabus is every non-statistics command in the syntax reference plus the nonsyntax manual documented features. I would probably skip macros, the matrix command set, scripts and Python--unless there is time to include them, and then, I'd do in the order listed. In addition, they need an understanding of how to setup data for different statisical procedures. Lastly, they need to know how to make spss output connect with other programs, especially word, excel and powerpoint. I'd say that to start with there are two required 'texts'. The syntax manual and Ray Levesque's book, which you can get from the spss website. If you go into scripts and Python, I don't know what documentation is available as there is nothing--as far as I can see--in the manuals directory. Maybe somebody else can say. Gene Maguin |
The Data Management book, referred to below, has been updated to the 4th edition, and it has greatly expanded content on programmability and Python. The third edition also has a lot of material on this topic.
If you have installed the programmability extension, you will find a large pdf file in the help/programmability subdirectory of your SPSS installation. And, of course, there are articles and other useful materials on SPSS Developer Central (www.spss.com/devcentral) -Jon Peck Gene Maguin <[hidden email]> Sent by: "SPSSX(r) Discussion" <[hidden email]> 01/12/2007 11:30 AM Please respond to Gene Maguin <[hidden email]> To [hidden email] cc Subject Re: Graduate course on SPSS Kim, I think that is an excellent idea. From time to time and when we can find them (and have the money to pay them), we have hired grad students to work on data management and analysis projects. I've noticed that their spss skills are pretty limited because they learned just enough of spss to get through a statistics lab. It sounds like you have something else in mind. I would assume that your students will have had a research design class(es) so that they will understand different designs and that they have had a (several) statistics class so that they understand how to conduct and interpret different statistical tests. Your class might fit into that area between design and statistics--an area I'd call 'data management and preparation'. I think your syllabus is every non-statistics command in the syntax reference plus the nonsyntax manual documented features. I would probably skip macros, the matrix command set, scripts and Python--unless there is time to include them, and then, I'd do in the order listed. In addition, they need an understanding of how to setup data for different statisical procedures. Lastly, they need to know how to make spss output connect with other programs, especially word, excel and powerpoint. I'd say that to start with there are two required 'texts'. The syntax manual and Ray Levesque's book, which you can get from the spss website. If you go into scripts and Python, I don't know what documentation is available as there is nothing--as far as I can see--in the manuals directory. Maybe somebody else can say. Gene Maguin |
In reply to this post by kim.barchard
Elena,
There may be some disagreement but I see the teaching of syntax as 'essential', not 'optional'. Some statistical options are not even available from the menu. However, most beginners and many advanced users may never miss those options. More to my point is that SPSS, SAS, Stata, etc. have made statistical analysis an almost mindless process. Before computers, statistical analysis was for those with the math skill, the need, motivation, perseverance, time, etc. to painstakingly march through columns of numbers and pages of matrices. You had to clean and condition your data manually, often on paper; a process that left you intimately (and I do mean 'intimately') familiar with your data. The process of calculating mean squares, sums of squares, and such gave you much more opportunity to find errors by recognizing intermediate values that seem a bit off. Then cam automation and the whole system went to pot. Now, all one needs to do is use one's familiarity with MS Windows to open a data set, pick a procedure, dump some variables into the box and pop out some parameter estimates. Sadly, with the removal of the math from the hands of beginning researchers, a vital step in the problem solving process (stepping back and reviewing your progress, checking the reasonableness of the numbers at intermediate steps) has been taken away. I think the ease at which statistics can be generated by computer has significantly increased the the risk of errors, particularly in the case of students. For my students and for myself, the use of syntax has provided us with a bit of that sense of intimacy that was lost when SPSS went Windows. The wonderful thing is you don't need to be a statistician to be a consciencious data manager. And you don't have to be a programmer to use syntax. You must only be willing to learn. Honestly, it's not like learning FORTRAN. There is a great deal a student can do with only some very simple syntax. In my experience, it only take a few weeks for students to appreciate how much time and effort syntax can save, especially when subsequent lessons require that they dip back into data and procedures that they have already run. They will quickly become confident and receptive to the idea of doing some things 'the old way'. The next thing you know they are playing with macros. Gene, Jon, and others have given some very good advice. Many books now teach SPSS by showing what syntax is produced when you set up a window and press 'PASTE' instead of 'OK'. I would recommend such books. I also have my students haunt Raynauld Levesque's website (http://www.spsstools.net/) and lurk on message boards. First and foremost, I demand that my students perform every procedure at least once using the 'PASTE' button rather than the 'OK' button. More on my 2-cents worth (note that it's not worth a dime). Mark *************************************************************************************************************************************************************** Mark A. Davenport Ph.D. Senior Research Analyst Office of Institutional Research The University of North Carolina at Greensboro 336.256.0395 [hidden email] 'An approximate answer to the right question is worth a good deal more than an exact answer to an approximate question.' --a paraphrase of J. W. Tukey (1962) "Elena Verbitskaya" <[hidden email]> 01/12/2007 12:49 PM To "'Mark A Davenport MADAVENP'" <[hidden email]> cc Subject RE: Graduate course on SPSS Dear Mark, I am sure you are right. Could you give me any advise in such situation: in Russia we do not have specialists in biostatistics in medical universities (we do not have such specialty at all), and all scientists have to do analysis themselves . We have organized some counseling (three persons in the laboratory), so we have to teach young scientist to do all themselves, they never have any information about programming, not all of them have good computer skills, but part have practice in calculating some basic statistics on calculators (only Student or so.)... Do you think it is wise to teach them syntax? Elena V. Verbitskaya -----Original Message----- From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Mark A Davenport MADAVENP Sent: Friday, January 12, 2007 8:27 PM To: [hidden email] Subject: Re: Graduate course on SPSS I replied to Kim privately with an attachment but want to give one more voice to the importance of Gene's comments. I see very few stats teachers going much deeper into SPSS that how to use the drop-down menus, leaving students with a very simplistic view of data analysis. SPSS is NOT a spread sheet. Students need to learn early on that SPSS is not just another expensive calculator. It's a tool for solving problems. For instance, it may take a student several finger-numbing mouse clicks to recreate contrast codes created, but messed up, in the previous day's work. Or he/she can simply open, edit, and run the syntax written the day before (not very sophisticated but it's a start): **COMPARE A1,B1 TO A2,B1 COMPUTE dummyc_1 = 0. DO IF (orglevel = 1 & gender = 1) . RECODE dummyc_1 (0=1) . END IF . DO IF (orglevel = 1 & gender = 2) . RECODE dummyc_1 (0=-1) . END IF . EXECUTE . We are very good at teaching students how to generate numbers. We could do so much more to help them learn how to solve data problems. For what it's worth. **************************************************************************** **************************************************************************** ******* Mark A. Davenport Ph.D. Senior Research Analyst Office of Institutional Research The University of North Carolina at Greensboro 336.256.0395 [hidden email] 'An approximate answer to the right question is worth a good deal more than an exact answer to an approximate question.' --a paraphrase of J. W. Tukey (1962) Gene Maguin <[hidden email]> Sent by: "SPSSX(r) Discussion" <[hidden email]> 01/12/2007 11:30 AM Please respond to Gene Maguin <[hidden email]> To [hidden email] cc Subject Re: Graduate course on SPSS Kim, I think that is an excellent idea. From time to time and when we can find them (and have the money to pay them), we have hired grad students to work on data management and analysis projects. I've noticed that their spss skills are pretty limited because they learned just enough of spss to get through a statistics lab. It sounds like you have something else in mind. I would assume that your students will have had a research design class(es) so that they will understand different designs and that they have had a (several) statistics class so that they understand how to conduct and interpret different statistical tests. Your class might fit into that area between design and statistics--an area I'd call 'data management and preparation'. I think your syllabus is every non-statistics command in the syntax reference plus the nonsyntax manual documented features. I would probably skip macros, the matrix command set, scripts and Python--unless there is time to include them, and then, I'd do in the order listed. In addition, they need an understanding of how to setup data for different statisical procedures. Lastly, they need to know how to make spss output connect with other programs, especially word, excel and powerpoint. I'd say that to start with there are two required 'texts'. The syntax manual and Ray Levesque's book, which you can get from the spss website. If you go into scripts and Python, I don't know what documentation is available as there is nothing--as far as I can see--in the manuals directory. Maybe somebody else can say. Gene Maguin |
In reply to this post by kim.barchard
At 10:29 AM 1/12/2007, [hidden email] wrote:
>I am thinking of teaching a course [that] would assume no background >with SPSS, but with bring students to a relatively high level of >sophistication. The course would focus on simple statistical >techniques so that this is a course about SPSS, not about statistics. Some points, recognizing that I'm partly echoing things other contributors have said. FIRST, learning SPSS has little to do with learning SPSS. (A special case of the principle that computing has little to do with computers.) That is, the crucial knowledge is what you need to do, and the steps *as* *viewed* *from* *the* *problem* to get there; only then, the syntax or techniques of your computational tool. SECOND, having said the above, you need to learn about your computational tool, SPSS or anything else; how it 'thinks'. For example, SPSS is a file-spinner; its most natural operation is reading and processing a file, record by record. The most important commands are those that work with a whole file (the procedures); those that get you a file to work with (start with GET FILE, DATA LIST); those that work with each record, 'case', as it goes by (the transformation commands); and those that define 'dictionary' attributes of the file ('transformation commands that take effect immediately'). That brings us to another part of how SPSS thinks: What a file 'looks' like. That is, the data types variables can have, attributes (name, labels, formats, missing values). THIRD, and this needs to be hammered in: much of the work on a statistical project, maybe 80%, is getting the data ready to run analyses on. That is *radically* absent from most exercises in statistics labs, where students never see anything but a cleaned-up file ready to go. Teach careful practice, finicky practice: label every variable; label values where that's relevant. Define user-missing values where that's useful (which is often). Specify a format, an appropriate format, for every numeric variable. (Neither categorical variables nor Likert scales should be F8.2) Of course, they'll have enough trouble getting the data in, in the first place. And then the computations to analyze it, like scale total scores where the variables read in are the question responses. And when you've done this, the descriptive statistics are to be read, with an eye to meaning and plausibility, not just printed and put in a binder. (For continuous variables, my usual set of descriptive statistics is mean, standard deviation, median, minimum, and maximum.) .................... Of course, you'll also need something to cover the SECOND day of the course. -Forwards or backwards, Richard; and the very best success to you. |
As usual Richard makes some very good points.
<tongue in cheek> The one point one which I would disagree is Richard Ristow wrote: > At 10:29 AM 1/12/2007, [hidden email] wrote: > <snip> > > THIRD, and this needs to be hammered in: much of the work on a > statistical project, maybe 80%, is getting the data ready to run > analyses on. > In consulting on something like over 200 doctoral dissertions and a thousand congressional investigations, I have seen a small handful of projects where it is as low as low as 80%. These tended to be using data from organizations such as Census, NCI, NIMH, or FDA. <remove tongue from cheek> Art Kendall Social Research Consultants |
In reply to this post by kim.barchard
Hi Kim
I'm joining this discussion a bit late (quite busy teaching SPSS to my students), but I hope to add a couple of ideas from my own experience teaching SPSS to biologists and medical researchers. Although all my teaching material is is Spanish, I think I could adapt part of it easily (a nice dataset and a flow-chart to select statistical methods) to English. Friday, January 12, 2007, 4:29:59 PM, You wrote: kbUE> I am thinking of teaching a graduate level course on SPSS. I'm imagining kbUE> that it would assume no background with SPSS, but with bring students to a kbUE> relatively high level of sophistication. The course would focus on simple kbUE> statistical techniques so that this is a course about SPSS, not about kbUE> statistics. How much time has spanned since your potential students learnt statistics theory? My own experience is that you can't try to teach them how to do a two-sample t-test with SPSS, if they don't know what a t-test is, why they should use it in that experimental situation and how to interpret SPSS output. My own courses intersperse statistics theory with SPSS teaching. kbUE> Does anyone have assignments and lectures they'd be willing to share? This is (schematically) the way I work (I have datasets for every analysis): BASIC COURSE (around 2/3 hours per session, some are longer than others) First session: -------------- The basics of dataset creation and manipulation with SPSS using the data editor, GUI and syntax Their goal is to create a dataset with 11 variables and 100 cases: * They start using the data editor (assigning "good" variable names, type -numeric, string, dates..., variable and value labels, variable level...), and typing the first two rows of data. The dataset is then saved (we are using SPSS 13, that doesn't allow simultaneous datasets). * The other 98 cases are stored in a text file (although I'm considering using an Excel file instead) and have to be imported to SPSS. The first dataset is then opened again and the second is added to it. The full dataset is saved. * Now, they are shown how to do that with syntax (DATA LIST, VAR LABEL, ADD FILES...) * New variables (using the GUI, and later the syntax): - Age (using the Date Wizard) is computed from BirthDate and StudyDate - BMI (body mass index) is computed from weight and height - Obesity is obtained recoding BMI into 3 categories (<25 Kg/m²=0; 25-30 Kg/m²=1; >30 Kg/m²=2) * Basic statistics: Frequencies, Descriptives, Explore... Second session: -------------- One and two-samples tests for continuous variables (parametric and non parametric). Each experimental situation is presented separately, with a small dataset, the flow chart is used to determine which statistical method answers the research question, and the full analysis is undertaken: Normality (or other conditions, like homogeneity of variances), parametric test (if normality was fulfilled), and non parametric equivalent (if normality failed). Although they use the GUI, they learn to click PASTE button instead of OK to see the underlying syntax. Some MACROS are used to add some statistical methods not covered by SPSS (like confidence intervals for median differences in paired and unpaired samples). We can't teach them how to write their own MACROS, but they learn the basics: what a MACRO is, and how activate and use it. Third session: ------------- K samples (continuous variables), both parametric and non parametric: Oneway ANOVA, Kruskal-Wallis, two-way ANOVA, repeated measures ANOVA and Friedman test. The same method as before: presentation of each experimental situation, flow chart to determine the correct statistical approach and full statistical analysis (normality, parametric and nonparametric). Again, MACROS are used (multiple comparisons after Kruskal-Wallis and Friedman test). VARTOCASES is used to stack the repeated measures dataset to analyse it using UNIANOVA (model without interaction). They use the GUI and the syntax is pasted. Fourth session: -------------- Correlation and regression Same method: presentation of a problem, using the flow chart to determine the correct approach. MACROS are used for bivariate normality, 95%CI for r and for nonparametric linear regression (Theil's incomplete method). Graphs are also used Fifth session: ------------- Methods for categorical variables: goodness of fit test, contingency tables (RxC and 2x2), McNemar's and Cochran's test (this last with a MACRO for multiple comparisons). The use of WEIGHT command is learnt (when aggregated data are presented). MACROs to compute confidence intervals for differences in proportions (both paired and unpared) are also used. ADVANCED COURSE The Basic course knowledge is assumed, and, again, the theory is explained before using SPSS. We focus on the following topics: - ANOVA models: randomized blocks, latin square, split-plot, nested models, mixed factorial model, pure within subjects factorial model, ANCOVAs. Both UNIANOVA and MIXED is used, and the syntax is manually modified (to nest some terms within others, or to add SPECIAL contrasts...) - Multiple linear regression. Strategies for model development; using a MACRO to center the interaction terms, model checking. - Categorical variables: stratified analysis (Mantel-Haenszel OR) and logistic regression. - Survival analysis: Kaplan-Meier and Cox regression. - Meta-analysis: with MACROS (you can find them at Devcentral). -- Regards, Dr. Marta García-Granero,PhD mailto:[hidden email] Statistician --- "It is unwise to use a statistical procedure whose use one does not understand. SPSS syntax guide cannot supply this knowledge, and it is certainly no substitute for the basic understanding of statistics and statistical thinking that is essential for the wise choice of methods and the correct interpretation of their results". (Adapted from WinPepi manual - I'm sure Joe Abrahmson will not mind) |
In reply to this post by Peck, Jon
All,
I think I know the answer to the analysis question; however, I want to make sure of that. A project I am working on will surveying two groups of people. Each group will be surveyed by two methods: A and B. Group 1 gets method A then B; Group 2 gets the reverse. The methods are related in that they ask abut the same topics but with different levels of detail and structure. We are expecting an interaction between method and group. Now then, the reason for my question. The DVs can be constructed as either dichotomies or counts. My understanding is that there is no way that spss can analyze this--without treating the DV as continuous. I can't think of anything that would work but is there something hiding or something that could be adapted? Question 2: Given the above design, can anyone offer any advice on how to compute a power number for this problem? Thanks, Gene Maguin |
In reply to this post by kim.barchard
Hi Marta and everyone else,
In my statistics courses, I teach students the theory, the hand calculation, and the SPSS calculation for each topic. My purpose in teaching students SPSS at that point is to teach them how to do the statistical analysis I have just taught them. With very few exceptions, these analyses can be done with menus, and if syntax files are absolutely essential, I provide them. Students become proficient at getting SPSS to do the analyses that I teach them in class. However, most psychological research goes beyond the statistical techniques taught in the two or three graduate level statistics courses that most psychologists get. And many psychological research projects would benefit from statistical techniques that cannot be done using the menu system. Therefore, I would like my students to feel confident in using SPSS in novel ways. Therefore, I was thinking of teaching a course on SPSS itself. This course would not teach much in the way of statistics. The goal would be to focus on SPSS. I would therefore assume knowledge of basic descriptive and inferential statistics (mean, sd, correlation, t-test), but nothing else. Each thing I teach students about SPSS, however, would need to be perceived as relevant and interesting and useful, or else students will resent the make-work activities, and will forget these skills when they would be most useful. Furthermore, unless they find the skills interesting and useful, they will not feel empowered to explore SPSS on their own. Therefore, each SPSS skill needs to be taught in the context of a real research question. It may be that teaching a course on SPSS itself is a bad idea. Perhaps SPSS should only be taught as part of a statistics or research methods course. By putting SPSS into the context of such a course, this provides a "story" for the skills being taught. One of the list members was talking about a course on data management. This would provide a story-line that includes defining variables and variable properties, merging files, transposing data, reorganizing data when it has been entered in a way that isn't condusive to analysis, etc. Another option would be a course in resampling techniques, which could introduce loops, and OMS. It is intersting to me that so far, no one has told me that they teach a course in SPSS itself. What do you think of the concept of a course that focusses on SPSS skills - how to go beyond the menus to use SPSS to answer research questions? Best regards, Kim Marta García-Granero <[hidden email]> writes: Hi Kim I'm joining this discussion a bit late (quite busy teaching SPSS to my students), but I hope to add a couple of ideas from my own experience teaching SPSS to biologists and medical researchers. Although all my teaching material is is Spanish, I think I could adapt part of it easily (a nice dataset and a flow-chart to select statistical methods) to English. Friday, January 12, 2007, 4:29:59 PM, You wrote: kbUE> I am thinking of teaching a graduate level course on SPSS. I'm imagining kbUE> that it would assume no background with SPSS, but with bring students to a kbUE> relatively high level of sophistication. The course would focus on simple kbUE> statistical techniques so that this is a course about SPSS, not about kbUE> statistics. How much time has spanned since your potential students learnt statistics theory? My own experience is that you can't try to teach them how to do a two-sample t-test with SPSS, if they don't know what a t-test is, why they should use it in that experimental situation and how to interpret SPSS output. My own courses intersperse statistics theory with SPSS teaching. kbUE> Does anyone have assignments and lectures they'd be willing to share? This is (schematically) the way I work (I have datasets for every analysis): BASIC COURSE (around 2/3 hours per session, some are longer than others) First session: -------------- The basics of dataset creation and manipulation with SPSS using the data editor, GUI and syntax Their goal is to create a dataset with 11 variables and 100 cases: * They start using the data editor (assigning "good" variable names, type -numeric, string, dates..., variable and value labels, variable level...), and typing the first two rows of data. The dataset is then saved (we are using SPSS 13, that doesn't allow simultaneous datasets). * The other 98 cases are stored in a text file (although I'm considering using an Excel file instead) and have to be imported to SPSS. The first dataset is then opened again and the second is added to it. The full dataset is saved. * Now, they are shown how to do that with syntax (DATA LIST, VAR LABEL, ADD FILES...) * New variables (using the GUI, and later the syntax): - Age (using the Date Wizard) is computed from BirthDate and StudyDate - BMI (body mass index) is computed from weight and height - Obesity is obtained recoding BMI into 3 categories (<25 Kg/m²=0; 25-30 Kg/m²=1; >30 Kg/m²=2) * Basic statistics: Frequencies, Descriptives, Explore... Second session: -------------- One and two-samples tests for continuous variables (parametric and non parametric). Each experimental situation is presented separately, with a small dataset, the flow chart is used to determine which statistical method answers the research question, and the full analysis is undertaken: Normality (or other conditions, like homogeneity of variances), parametric test (if normality was fulfilled), and non parametric equivalent (if normality failed). Although they use the GUI, they learn to click PASTE button instead of OK to see the underlying syntax. Some MACROS are used to add some statistical methods not covered by SPSS (like confidence intervals for median differences in paired and unpaired samples). We can't teach them how to write their own MACROS, but they learn the basics: what a MACRO is, and how activate and use it. Third session: ------------- K samples (continuous variables), both parametric and non parametric: Oneway ANOVA, Kruskal-Wallis, two-way ANOVA, repeated measures ANOVA and Friedman test. The same method as before: presentation of each experimental situation, flow chart to determine the correct statistical approach and full statistical analysis (normality, parametric and nonparametric). Again, MACROS are used (multiple comparisons after Kruskal-Wallis and Friedman test). VARTOCASES is used to stack the repeated measures dataset to analyse it using UNIANOVA (model without interaction). They use the GUI and the syntax is pasted. Fourth session: -------------- Correlation and regression Same method: presentation of a problem, using the flow chart to determine the correct approach. MACROS are used for bivariate normality, 95%CI for r and for nonparametric linear regression (Theil's incomplete method). Graphs are also used Fifth session: ------------- Methods for categorical variables: goodness of fit test, contingency tables (RxC and 2x2), McNemar's and Cochran's test (this last with a MACRO for multiple comparisons). The use of WEIGHT command is learnt (when aggregated data are presented). MACROs to compute confidence intervals for differences in proportions (both paired and unpared) are also used. ADVANCED COURSE The Basic course knowledge is assumed, and, again, the theory is explained before using SPSS. We focus on the following topics: - ANOVA models: randomized blocks, latin square, split-plot, nested models, mixed factorial model, pure within subjects factorial model, ANCOVAs. Both UNIANOVA and MIXED is used, and the syntax is manually modified (to nest some terms within others, or to add SPECIAL contrasts...) - Multiple linear regression. Strategies for model development; using a MACRO to center the interaction terms, model checking. - Categorical variables: stratified analysis (Mantel-Haenszel OR) and logistic regression. - Survival analysis: Kaplan-Meier and Cox regression. - Meta-analysis: with MACROS (you can find them at Devcentral). -- Regards, Dr. Marta García-Granero,PhD mailto:[hidden email] Statistician |
At 06:08 PM 1/15/2007, [hidden email] wrote:
>It may be that teaching a course on SPSS itself is a bad idea. Perhaps >SPSS should only be taught as part of a statistics or research methods >course. By putting SPSS into the context of such a course, this >provides a "story" for the skills being taught. Let me try an analogy: teaching English composition. (Will members forgive me for writing 'English composition', on a multi-national list? English is the only language in which I know rhetoric well. I take the liberty of using it as my example, not being sure how techniques of rhetoric, and the teaching of it, may differ in other countries and languages.) To write competently, you need to know a lot about English, and about rhetoric. (By the latter, I mean techniques like stating and then expanding a topic; controlling the rhythm of sentences; order of topics, to put the emphasis where you desire it.) But no matter how much you know about either, you can't write unless you have something to say. Teaching composition is mainly asking students to write, short and then longer pieces, on assigned topics. You teach grammar, rhythm, and rhetoric. But you don't give tests on students' knowledge of them; you evaluate how students apply them, in what they write. Following the analogy, students should learn SPSS through 'stories'; but probably not a single 'story' for the course. That could be as daunting, and as limiting, as organizing a composition course around writing a single large paper. There should, then, be different tasks to accomplish in SPSS: read data and error-check it; descriptive statistics; simple, and complex, inferential procedures. Marta's course is like that. I'd consider more of the 'first session' topics, preparing data for analysis. Maybe several input sets, in varying degrees of cleanliness. (Marta, I'd be inclined to stick with text, rather than Excel. Text forces more careful thinking about what are your variables, what your datatypes.) Descriptive statistics isn't something to toss off. What does a frequency table tell you; what, in a frequency table, suggests you need to think further? What statistics give you a good picture of a continuous variable; how do you 'see' that picture? (As one example: What do you learn from how near the mean and median are, to each other?) Then, simple inferential statistics. Descriptive statistics often shade into these: correlations; simple chi-square or t/ANOVA tests for differences across groups; are themselves a part of 'seeing' a dataset. (Your students may balk: why all this simple stuff, when we want to do GLM? Part of the course is teaching the subtlety of the 'simple'.) Of course, they do each exercise in SPSS. How far they write syntax and how far use the menus is your judgement. A suggestion, though: they should always paste and run the syntax from the menus, and turn in that syntax as part of their work. I imagine exercises in changing a table in a certain way, by editing the syntax (menus not allowed). >In my statistics courses, I teach students the theory, the hand >calculation, and the SPSS calculation for each topic. My purpose in >teaching students SPSS at that point is to teach them how to do the >statistical analysis I have just taught them. With very few >exceptions, these analyses can be done with menus, and if syntax files >are absolutely essential, I provide them. Students become proficient >at getting SPSS to do the analyses that I teach them in class. Fair enough, but give SPSS its place, and not in the background. I think they should always see the syntax they are running. And, though I don't know how to teach it, to see a file as a live thing, not a dull dead source of statistics. >Each thing I teach students about SPSS, however, would need to be >perceived as relevant and interesting and useful, or else students >will resent the make-work activities, and will forget these skills >when they would be most useful. Furthermore, unless they find the >skills interesting and useful, they will not feel empowered to explore >SPSS on their own. Therefore, each SPSS skill needs to be taught in >the context of a real research question. Yes, though that should include some very simple ones. They'll think of descriptive statistics as something you toss off on the way to the real work. They'll resist learning, but need to learn, that if you don't know your data from the descriptives, you can mislead yourself badly in the analysis. >One of the list members was talking about a course on data >management. This would provide a story-line that includes defining >variables and variable properties, merging files, transposing data, >reorganizing data when it has been entered in a way that isn't >conducive to analysis, etc. Don't know if you meant what I wrote. I certainly suggested something like this. BUT, it should be data management as a means to understand the data, not management for the sake of management. >Another option would be a course in resampling techniques, which could >introduce loops, and OMS. Better not do this at the beginning. Those are *subtle* techniques, for someone who doesn't understand SPSS basics, deeply. >It is interesting to me that so far, no one has told me that they >teach a course in SPSS itself. Well, maybe this is why - the same reason nobody (in English-speaking countries) teaches English, though students need to know it much better than they do. You teach English by teaching the use of it. >What do you think of the concept of a course that focuses on SPSS >skills - how to go beyond the menus to use SPSS to answer research >questions? Yes, but I repeat: Every research project stands or falls on how well the data's read, organized, and understood. Learn that, and you're ready to go somewhere. -In joy and Light, Richard |
At 04:21 PM 1/15/2007, Richard Ristow wrote:
>At 06:08 PM 1/15/2007, [hidden email] wrote: > >>It may be that teaching a course on SPSS itself is a bad idea. Perhaps >>SPSS should only be taught as part of a statistics or research methods >>course. . . . >Let me try an analogy: teaching English composition. . . . >To write competently, you need to know a lot about English, and about >rhetoric. (By the latter, I mean techniques like stating and then >expanding a topic; controlling the rhythm of sentences; order of >topics, to put the emphasis where you desire it.) > >But no matter how much you know about either, you can't write unless >you have something to say. . . . I'd like to take a different tack with this argument. To me, SPSS is a *tool*. I'll make a more extreme metaphor-- let's compare SPSS to a hammer. Would you teach a course in uses of the hammer? That metaphor leads us to considering the use of SPSS as a tool in implementation of the hypothetico-deductive method, which I think is mostly the way to do it. What you're trying to do, I think, is more in keeping with exploratory data analysis: >Descriptive statistics isn't something to toss off. What does a >frequency table tell you; what, in a frequency table, suggests you need >to think further? What statistics give you a good picture of a >continuous variable; how do you 'see' that picture? (As one example: >What do you learn from how near the mean and median are, to each other?) This type of analysis is especially useful in the early stages of analysis, especially as a data screening exercise. This is an especially good time to notice the minimums and maximums, and consider whether or not those values are reasonable for those variables. For example, I recently noticed values such as "33," "13," and "11" for variables that were Likert scales with values ranging from 1 to 5. Noticing the shape of distributions can also be quite useful, especially if the distribution is bimodal. >Then, simple inferential statistics. Descriptive statistics often shade >into these: correlations; simple chi-square or t/ANOVA tests for >differences across groups; are themselves a part of 'seeing' a dataset. IMHO this part should be taught along with the hypothetico-deductive method and hypothesis testing. Again IMHO, EVERY student should know what testing a hypothesis means and how to do it. They should also know what "testing the null hypothesis" means, because unless one knows about that, using SPSS will likely mean merely pushing numbers around. One of the reasons that I like about the old chestnut on social statistics by Blalock is that on the inside cover was a table showing what chapter to look in if your Independent variable is, say, ordinal and your dependent variable is scale.(or any other pair of variable types). This covers most of what you need to know to test a bivariate hypothesis. >. . . Of course, they do each exercise in SPSS. How far they write syntax and >how far use the menus is your judgement. A suggestion, though: they >should always paste and run the syntax from the menus, and turn in that >syntax as part of their work. I imagine exercises in changing a table >in a certain way, by editing the syntax (menus not allowed). I would be more interested in their understanding of research design, and would not be so interested in whether or not they used syntax. But I'd also give'em a few problems that can really only be done using syntax. >>. . . One of the list members was talking about a course on data >>management. This would provide a story-line that includes defining >>variables and variable properties, merging files, transposing data, >>reorganizing data when it has been entered in a way that isn't >>conducive to analysis, etc. One of the most important things is teaching them the difference between coding that makes data entry easier, vs. coding that makes it easier to conduct an analysis. There are lots of ways of inputting data that make data input easy, but may make data analysis much more difficult-- and vice versa. >>It is interesting to me that so far, no one has told me that they >>teach a course in SPSS itself. This is because SPSS is/should be viewed as a tool, not as an end in itself. >. . . Every research project stands or falls on how well >the data's read, organized, and understood. Learn that, and you're >ready to go somewhere. Understood? Aye, there's the rub. Bob |
In reply to this post by Maguin, Eugene
Gene,
If I understand correctly, you have data that could look something like: id group method order depvar 1 1 A 1 n1A 1 1 B 2 n1B 2 2 A 2 n2A 2 2 B 1 n2B 3 1 A 1 n1A 3 1 B 2 n1B 4 2 A 2 n2A 4 2 B 1 n2B Where "id" is the subject id, "order" is the order in which the group members took that method, and "depvar" contains counts. So you could fit, for example: GENLIN depvar BY group method order /MODEL group method group*method DISTRIBUTION=POISSON LINK=LOG /REPEATED SUBJECT=id WITHINSUBJECT=order CORRTYPE=EXCHANGEABLE /PRINT MODELINFO FIT SUMMARY SOLUTION WORKINGCORR. This GENLIN syntax is adapted from the MIXED pasted syntax from the "Using Linear Mixed Models to Analyze a Crossover Trial" case study (Help > Case Studies; then Advanced Models > Linear Mixed Models); the specification is a little different in Genlin, but some of the same issues with crossover trials would apply, I think. In Genlin, of course, you will also want to take care with your choice of link function and distribution. Not sure about question 2; have you talked to statistical Tech Support? Cheers, Alex -----Original Message----- From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Gene Maguin Sent: Monday, January 15, 2007 2:30 PM To: [hidden email] Subject: An analysis question and a power question All, I think I know the answer to the analysis question; however, I want to make sure of that. A project I am working on will surveying two groups of people. Each group will be surveyed by two methods: A and B. Group 1 gets method A then B; Group 2 gets the reverse. The methods are related in that they ask abut the same topics but with different levels of detail and structure. We are expecting an interaction between method and group. Now then, the reason for my question. The DVs can be constructed as either dichotomies or counts. My understanding is that there is no way that spss can analyze this--without treating the DV as continuous. I can't think of anything that would work but is there something hiding or something that could be adapted? Question 2: Given the above design, can anyone offer any advice on how to compute a power number for this problem? Thanks, Gene Maguin |
Alex,
Yes, that is what the data would look like when arranged in a univariate structure. Genlin is in 15 is it not? We are using 14. Ok, so that's that. Thank you. Gene Maguin |
In reply to this post by Marta García-Granero
Hi everybody
After being delayed for several days (duties at the University, trying to force.. er, ahem!, TEACH some basic SPSS handling knowledge to my students), I'm back with the original topic. SPSS experts can safely skip this message, it is dedicated to novel users. OK, here's my idea of what a first session with SPSS could be. Anyone interested in the GUI version of this can ask for an Acrobat file with the screenshots and all (unfortunately, in Spanish, and I don't plan to translate it yet, too busy for that...). The rest of the GUI related material belongs now to the University - although I did all the writing - (only the first chapter could be considered "free") and can't be sent, sorry. I can also send the text file with the data to be imported, but anyone with a bit of knowledge can get their own as I did (random generation of values). Tomorrow I'll start the series from one sample testing (parametric&non parametric) to factorial ANOVA, correlation & regression, to finish with categorical data (from goodness of fit to McNemar & Cochran tests for related samples). I'll need some time to translate the accompanying MACROS. CREATION OF A DATASET WITH SPSS 13 AND SOME BASIC HANDLING * Creating dataset with only two first cases *. DATA LIST LIST/id(F4) name(A8) birthdate studydate (2 EDATE10) gender(F5) height weight initDPB endDBP initSPB endSBP (6 F4). BEGIN DATA 1 RPL 28-08-1941 13-07-1998 1 164 78 78 104 176 175 2 IGZ 30-06-1957 09-05-1998 1 155 74 95 114 162 160 END DATA. * Format and labels *. VARIABLE LABEL id 'ID Number' /name 'Name' /birthdate 'Birth Date' /studydate 'Study Date' /gender 'Gender' /height 'Height (cm)' /weight 'Weight (kg)' /initDPB 'Initial Diastolic Blood Pressure (mmHg)' /endDBP 'Final Diastolic Blood Pressure (mmHg)' /initSPB 'Initial Systolic Blood Pressure (mmHg)' /endSBP 'Final Systolic Blood Pressure (mmHg)'. VALUE LABEL gender 0 'Male' 1 'Female'. VARIABLE WIDTH birthdate studydate(10). VARIABLE LEVEL gender (NOMINAL). * Save dataset for later (SPSS 13 - only one dataset - is used) *. SAVE OUTFILE='C:\SPSS Datasets&Syntax Files\Hypertension Dataset.sav'. * Next tasks can be (and will be, in due time), modified for SPSS 14/15 and its multiple dataset handling capabilities: *. * Import the rest of the data (careful with variable names and types) *. GET DATA /TYPE = TXT /FILE = 'C:\SPSS Datasets&Syntax Files\Data(3-100).txt' /DELCASE = LINE /DELIMITERS = " " /ARRANGEMENT = DELIMITED /FIRSTCASE = 1 /IMPORTCASE = ALL /VARIABLES = id F4 name A8 birthdate EDATE10 studydate EDATE10 gender F5 height F4 weight F4 initDPB F4 endDBP F4 initSPB F4 endSBP F4. SAVE OUTFILE='C:\SPSS Datasets&Syntax Files\Data(3-100).sav'. * Get original file again and add the second at the end *. GET FILE'C:\SPSS Datasets&Syntax Files\Hypertension Dataset.sav'. ADD FILES /FILE=* /FILE='C:\SPSS Datasets&Syntax Files\Data(3-100).sav'. EXE. /* Only if you want to see the results in the Data Editor *. * 4 new variables (using different SPSS "tricks") *. COMPUTE age = DATEDIF(studydate, birthdate, "years"). COMPUTE bmi = weight/((height/100)**2). RECODE bmi (Lowest thru 25=0) (25 thru 30=1) (30 thru Highest=2) INTO obesity . DO IF (initDPB GT 90) OR (initSPB GT 140). . COMPUTE initHT=1. ELSE. . COMPUTE initHT=0. FORMATS age obesity initHT (F5.0). VARIABLE LABEL age 'Age (years)'/ bmi 'Body Mass Index (Kg/m²)'/ obesity 'Presence of obesity'/ initHT 'Initial Hypertension'. VAL LAB obesity 0 'No' 1 'Overweight' 2 'Obese'/ initHT 0 'No' 1 'Yes'. VAR WIDTH age bmi obesity (8). VAR LEV obesity (ORDINAL) initHT (NOMINAL). * Complete dataset is saved to disk *. SAVE OUTFILE='C:\SPSS Datasets&Syntax Files\Hypertension Dataset.sav'. * Some very basic analyses *. FREQUENCIES VARIABLES=gender obesity initHT /PIECHART FREQ. FREQUENCIES VARIABLES=height to bmi /FORMAT=NOTABLE /NTILES= 4 /STATISTICS=STDDEV MIN MAX MEAN SKEW SESKEW KURT SEKURT /HISTOGRAM=NORMAL. EXAMINE VARIABLES=height to bmi /PLOT=BOXPLOT /STATISTICS=NONE. That's all. By the way, Richard, I agree that showing how to use SPSS without a clear purpose is, at the very least, quite difficult (more than usual, I mean, my students are always so reluctant to be taught, I think I have got only 2, out of 120, that are really interested in learning more...). RR> At 05:28 AM 1/15/2007, you wrote: >>I hope to add a couple of ideas from my own experience teaching SPSS >>to biologists and medical researchers. I think I could adapt part of >>[my teaching material] easily methods) to English. RR> What can I say? Yay, yay, Marta. All the good ideas the rest of us have RR> posted, but farther, better, and in an actual course outline. -- Regards, Dr. Marta García-Granero,PhD mailto:[hidden email] Statistician --- "It is unwise to use a statistical procedure whose use one does not understand. SPSS syntax guide cannot supply this knowledge, and it is certainly no substitute for the basic understanding of statistics and statistical thinking that is essential for the wise choice of methods and the correct interpretation of their results". (Adapted from WinPepi manual - I'm sure Joe Abrahmson will not mind) |
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