tag:blogger.com,1999:blog-8909074830238091680.comments2014-07-25T15:04:00.366+10:00Jeromy Anglim's Blog: Psychology and StatisticsJeromy Anglimnoreply@blogger.comBlogger775125tag:blogger.com,1999:blog-8909074830238091680.post-24457663224213667662014-07-08T20:29:12.836+10:002014-07-08T20:29:12.836+10:00Hi Jeromy,
I have a data set containing 30 Binar...Hi Jeromy,<br /><br />I have a data set containing 30 Binary Variables (1,0) . I would like to perform SEM on these 30 Binary Variables against 4 Dependent Variables. Can you please explain the step by step procedure in R to perform the SEM analysis (R Code)Avinshhttp://www.blogger.com/profile/14272266272192325792noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-11588539162649585572014-05-29T23:53:03.814+10:002014-05-29T23:53:03.814+10:00I am the first timer for using apacite, and got th...I am the first timer for using apacite, and got the following error message:<br /><br />!undefined control sequence. <br />1.1216 \st@rtbibchapter<br /><br />What's this? Thanks. Lihui Baihttp://www.blogger.com/profile/10038624117089266350noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-50547165731347114682014-05-23T16:29:21.122+10:002014-05-23T16:29:21.122+10:00A great new course for beginners on youtube, has g...A great new course for beginners on youtube, has great content with short and crisp videos. Easy to follow. New content is getting added, So I suggest to subscribe.<br />https://www.youtube.com/watch?v=BGWVASxyow8&index=18&list=PLFAYD0dt5xCzTQHDhMPZwBoaAXWeVhZzgSelva Prabhakaranhttp://www.blogger.com/profile/05519694374996247829noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-56990377886806817392014-05-06T20:38:28.865+10:002014-05-06T20:38:28.865+10:00how to find relative importance index using spss f...how to find relative importance index using spss for my likert scale data??Harrison Yanhttp://www.blogger.com/profile/12366111009273933160noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-56099438351326313502014-05-02T15:27:53.752+10:002014-05-02T15:27:53.752+10:00I guess you could use the traditional graphics dev...I guess you could use the traditional graphics devices like png and pdf<br />http://stat.ethz.ch/R-manual/R-devel/library/grDevices/html/Devices.html<br /><br />Otherwise, I'm not sure. I guess you could scan the knitr options, but I haven't seen anything designed to do this: http://stat.ethz.ch/R-manual/R-devel/library/grDevices/html/Devices.htmlJeromy Anglimhttp://www.blogger.com/profile/12949204812496382042noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-74402952848704416142014-05-02T13:08:43.370+10:002014-05-02T13:08:43.370+10:00Great cheat sheet for knitr newbies, thanks! I hav...Great cheat sheet for knitr newbies, thanks! I have a follow-up, though. Each chunk generates a .png, which default name is the name of the chunk. For example,<br />```{r ChunkName}<br /> p<-ggplot(ds, aes(x=varible1))<br /> p<-p+geom_bar()<br /> print(p)<br />```<br />will produce a .png named "ChunkName.png"<br /><br />If there are a several graphs to be produced by the same chunk, they will be automatically ordered. So<br />```{r ChunkName}<br />years <- 1997:1999<br />for (year in years){<br /> p<-ggplot(ds[ds$year==year,], aes(x=variable1))<br /> p<-p+geom_bar()<br /> print(p)<br />}<br />}<br />```<br />will produce 3 graphs: "ChunkName1.png", "ChunkName2.png" and "ChunkName3.png". However, I'd like to name the pngs myself, tying them to some automatic variable (like year, in this example), so that it produced something like<br />"ChunkName_1997.png", "ChunkName_1998.png" and "ChunkName_1999.png". <br /><br />Any ideas how to override the defaults? <br /><br /><br />Андрей Ковальhttp://www.blogger.com/profile/14264243871276423056noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-16398006946768038312014-05-02T00:03:17.564+10:002014-05-02T00:03:17.564+10:00Dear Jeromy,
is there a chance that you could hav...Dear Jeromy,<br /><br />is there a chance that you could have a look at my question about modeling nominal variables in JAGS ?<br /><br />http://stats.stackexchange.com/questions/95929/bugs-jags-for-nominal-response-model<br /><br />thank you very much<br /><br />J.k1111http://www.blogger.com/profile/11449275035410259115noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-84116919026177307512014-04-26T14:52:14.291+10:002014-04-26T14:52:14.291+10:00That's what this post is about. What do you wa...That's what this post is about. What do you want to know?Jeromy Anglimhttp://www.blogger.com/profile/12949204812496382042noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-75939253518365646032014-04-26T14:51:15.047+10:002014-04-26T14:51:15.047+10:001. r means correlation; r12 means correlation betw...1. r means correlation; r12 means correlation between variable 1 and variable 2<br /><br />2. N means total sample size<br /><br />3 and 4. the symbol means square rootJeromy Anglimhttp://www.blogger.com/profile/12949204812496382042noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-29638797646702761342014-04-25T09:16:35.793+10:002014-04-25T09:16:35.793+10:00Concerning Hotelling's T-test for "corre...Concerning Hotelling's T-test for "correlated correlations", I have some questions about the formula<br />1. r: what does "r" mean like r12?<br />2. df=N-3: What does "N" mean? Does N mean the sample size?<br />3. √ [N-3]: What does "√" mean? <br />4. √ 2: What does "√" mean?<br />Chun-Lan Changhttp://www.blogger.com/profile/14343630378681915325noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-61859015692889431452014-04-24T19:11:39.611+10:002014-04-24T19:11:39.611+10:00If there are three quantitative variables: x, y, a...If there are three quantitative variables: x, y, and z, how to perform dependent correlation analysis? Thanks.Chun-Lan Changhttp://www.blogger.com/profile/14343630378681915325noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-80327314929300406362014-04-15T18:28:19.303+10:002014-04-15T18:28:19.303+10:00Thanks for this article. I spent about an hour try...Thanks for this article. I spent about an hour trying to figure out scoreItems {psych} using >help(scoreItems) ... 10 minutes after reading this and I finished my script. Brilliant. Thanks again.<br /><br />@ste_nickstenick1989http://www.blogger.com/profile/04791920896372981288noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-33638238211471711552014-03-28T22:14:44.033+11:002014-03-28T22:14:44.033+11:00Ahh i see.
I meant the subject couldn't perf...Ahh i see. <br /><br />I meant the subject couldn't perform the test ( single leg balance). She couldn't even hold it for a second. The actual tests gets over this by using a scale which gives points from 1- 100. So for unattempted task you get 0 points. But i don't have their scores hence. <br /><br />And you should write an E book. I will buy it. Anoopbalhttp://www.blogger.com/profile/17871276618033328611noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-69427430088461570572014-03-28T12:37:42.187+11:002014-03-28T12:37:42.187+11:00the standard deviation of component variables is t...the standard deviation of component variables is the same with z-scores. Thus, composites of z-scores effectively weight components equally.<br /><br />I'm not sure what you mean by could not do a test. You could mean did not sit the test, which means you have missing data. Or you could mean failed the test, which presumably means you have an issue of how to score a test where people vary on both how well they did something and whether they could do it at all.<br /><br />With missing data, there are many approaches. One simple one, i just to take the mean score for the data you do have on the person as long as they still have a certain number of scores. This is equivalent to imputing the person mean to the missing data. That said, missing data analysis is a complex issue.<br /><br />If it's an issue of how to score a test where you have some that failed, then that is really going to require some domain specific knowledge. In general, if you want to put all these people on the one scale, then I think at the very least someone who can not do a test at all should generally get a score worse than those who could do it but did it poorly.Jeromy Anglimhttp://www.blogger.com/profile/12949204812496382042noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-6344594076611047332014-03-28T12:30:29.131+11:002014-03-28T12:30:29.131+11:00Is it because the standard deviation is similar wi...Is it because the standard deviation is similar with z scores ? But when you combine scores by adding the standard deviations could be very different. <br /><br />Also what do you when someone couldn't do the test or scores a zero ( like balance). And this test is time based so if I give zero it means she did it very very good. What do you suggest in this case? Thank you so muchAnoopbalhttp://www.blogger.com/profile/17871276618033328611noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-89140458551859609252014-03-28T11:43:40.642+11:002014-03-28T11:43:40.642+11:00You are going to get a different variable when you...You are going to get a different variable when you take a composite. Often it will be a more reliable variable. <br /><br />It's certainly possible to get a significant composite and for all the components to be non-significant. <br />There are several explanations for this.<br />The general statistical answer is that if several of the composites are close to significant and in the same direction (e.g., p=.09, p=.1, p=.15) then the combined variable may be enough to be statistically significant at .05.<br /><br />Equally, you could get the opposite where one or more of the components is significant but the composite is not.<br /><br />It's interesting to ponder whether the underlying effect size would be larger for composites or components. In general the increased reliability associated with composites and their more general nature, may lead to generally larger effect sizes. But this is certainly not guaranteed. <br /><br />Another nice thing about the composite is that it provides an overall test. When you have many component variables, you have issues of multiple testing (i.e., with associated increased risks of Type I errors).<br />Jeromy Anglimhttp://www.blogger.com/profile/12949204812496382042noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-62501164341915715362014-03-28T02:30:31.876+11:002014-03-28T02:30:31.876+11:00I know composites gives an overall assessment of m...I know composites gives an overall assessment of multiple tests. But is there any statistical benefits to using composites?<br /><br />I have noticed in my composite scores, the composite turned out to be significant, but the individual components are not. I used the z scores to calculate composites of 3 variables.<br /><br />Why is this? Thank you so muchAnoopbalhttp://www.blogger.com/profile/17871276618033328611noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-57102316649863974812014-03-27T17:24:59.071+11:002014-03-27T17:24:59.071+11:00Awesome article! If you haven't yet, you shoul...Awesome article! If you haven't yet, you should check out careerexchange.com.au , it's an Australian job board for allied health professionals, so it's a good place to look for jobs in psychology. It also has tips and tricks that are especially relevant to allied health professions. Psych Presshttp://www.blogger.com/profile/08795617839123104566noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-18443374036269236942014-03-26T13:04:51.282+11:002014-03-26T13:04:51.282+11:00I'm not really sure what you are talking about...I'm not really sure what you are talking about. I know when people get reaction time data with many observations per participant that they sometimes extract individual quantiles to reflect aspects of each individual's reaction time distribution. This gives you more than just the mean which is particularly useful where the data is non-normal or contains outliers or where you where the variance is relevant and differs between people.Jeromy Anglimhttp://www.blogger.com/profile/12949204812496382042noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-83947755194889862302014-03-26T12:29:28.280+11:002014-03-26T12:29:28.280+11:00Just came across this post: Have you seen composit...Just came across this post: Have you seen composite scores based on quartiles? I have seen tests which cuts the scores into quartiles and give them points , like 12. What is the advantage of doing this way? Thank you for your postings!Anoopbalhttp://www.blogger.com/profile/17871276618033328611noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-70691670624582048672014-03-14T02:03:43.740+11:002014-03-14T02:03:43.740+11:00Stephan, thanks for clearing that up. I am left wi...Stephan, thanks for clearing that up. I am left with one last hurdle, the bibliography part. I have always used <br />\begin{thebibliography}{99}<br />\bibitem{xxx}<br />\emph{xxxx}<br />but now, it is saying control sequence not recognized. How do I change the bibliography to work with apacite?.Sydney Muzokahttp://www.blogger.com/profile/07889282574552809816noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-56719094529124293342014-03-10T10:47:30.928+11:002014-03-10T10:47:30.928+11:00There are several options; the simplest would be t...There are several options; the simplest would be to convert to a z-score using analyze - descriptives -descriptives save as standardised variable.Jeromy Anglimhttp://www.blogger.com/profile/12949204812496382042noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-90642097251463220422014-03-10T04:54:25.264+11:002014-03-10T04:54:25.264+11:00Hello Jeromy! This post is a great resource and I&...Hello Jeromy! This post is a great resource and I've learned a lot from it. For creating some basic (i.e., equally weighted) composite variables it was perfect! Now I'm trying to take the OPQ32r and map it to a 6 factor model of personality. I have the sten scores for the 32 components of the OPQ. The publishers manual provides a mapping to the 6 factor model (i.e., the rotated component matrix). I am trying to create composite variables using the components that have weights above .3 (including negative weights; i.e., humility has a negative relationship with extraversion). Once I create the composite variables, however, the means and standard deviations are no longer meaningful. I've seen people mention that you should rescale your composite to make it meaningful/interpretable again, but the only example that I found was in R and I couldn't follow it at all. I'm using SPSS. Any tips or guidance would be much appreciated. Thanks! n.gintherhttp://www.blogger.com/profile/02613093288733640382noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-243181964110232612014-03-06T06:48:01.976+11:002014-03-06T06:48:01.976+11:00Hey Jeromy thank you so much for posting all the l...Hey Jeromy thank you so much for posting all the lectures and data. This has helped me better articulate the use of particular techniques in both SPSS and R! Keep up the good work.Simmyhttp://www.blogger.com/profile/04181813388093190303noreply@blogger.comtag:blogger.com,1999:blog-8909074830238091680.post-5554635110301983202014-03-03T04:46:04.805+11:002014-03-03T04:46:04.805+11:00A nice tip is to Set Endnote to use page-range as ...A nice tip is to Set Endnote to use page-range as its identifier (rather than the random internal ID sequence it uses by default).<br /><br />References are then inserted like this {Anglin, 2013, 89-90}<br /><br />That makes them transportable and recoverable.<br /><br />I also set up a key-command in word/endnote for "insert selected reference", then once you have the ref in Endnote, it's trivial to replace it in the word document.<br /><br />I use ^⌥-1 as the key (and ^⌥-1 as the short cut for building the bibliography)<br />Timothy Bateshttp://www.blogger.com/profile/12707381996365946983noreply@blogger.com