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Psychological statistics, quantitative psychology. Statistics in social sciences. Experimental design, data analysis.enFri, 24 Mar 2017 15:28:21 GMTvBulletin60http://www.talkstats.com/images/misc/rss.pngStatistics Help @ Talk Stats Forum - Psychology Statistics
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<![CDATA[Signal Detection Theory - Calculating d']]>
http://www.talkstats.com/showthread.php/69054-Signal-Detection-Theory-Calculating-d?goto=newpost
Thu, 23 Mar 2017 15:56:08 GMTHi there. I'm currently doing the analysis for my undergraduate study, and I'm wondering if someone could help me with Signal Detection Theory, specifically calculating d'.

My research paradigm is:
Participant sees a stream of images. In the test phase, they have to decide which image from a choice of 2 was originally presented.

This has allowed me to calculate a hit rate proportion and a false alarm proportion for each image in the study.

I'm aware d' = z(hit rate)-z(false alarm rate)

I have converted my hit rate and false alarm proportions into z scores using the descriptive statistics menu on SPSS. So in order to get d', do I just subtract false alarm rate from hit rate?

Also - some of my FAs are zeros. What's the best way to overcome this?

Hope someone can explain in laypeople's terms- I am very new to this theory.

Thanks in advance,
:):tup:
]]>Psychology Statisticsiwsmuir105http://www.talkstats.com/showthread.php/69054-Signal-Detection-Theory-Calculating-dCorrect way of reporting Chi square with IV 4 levels results
http://www.talkstats.com/showthread.php/69052-Correct-way-of-reporting-Chi-square-with-IV-4-levels-results?goto=newpost
Thu, 23 Mar 2017 12:28:56 GMTSorry, if the question is silly. Cannot find anywhere what will be a correct way of reporting Chi Square results for the case when IV has 4 levels (4...Sorry, if the question is silly. Cannot find anywhere what will be a correct way of reporting Chi Square results for the case when IV has 4 levels (4 different nationalities)? The study was checking differences between personal experiences descriptions for participants from 4 different countries, all DV are dichotomous.
]]>Psychology StatisticsLilianahttp://www.talkstats.com/showthread.php/69052-Correct-way-of-reporting-Chi-square-with-IV-4-levels-resultsNeed help in Polynomial Regression : constant value and control variables
http://www.talkstats.com/showthread.php/69048-Need-help-in-Polynomial-Regression-constant-value-and-control-variables?goto=newpost
Thu, 23 Mar 2017 04:50:49 GMTDear all,
I am running my data using Polynomial Regression. The variables are all measured on 6-point Likert-type scales. I run Polynomial...Dear all,

I am running my data using Polynomial Regression. The variables are all measured on 6-point Likert-type scales. I run Polynomial Regression in SPSS and and I center the predictors at 3.5 (which is the midpoint of 6-point Likert-type scales). The mean values of all variables are ranged from 3.8-4.2. However, my constant value is 5.78 and it seems to be too high as from my understanding constant value helps to predict the mean value of the outcome variable when the predictors are 0. The constant value is 4.2 when I didn't add the control variables.
Need help in Polynomial Regression : constant value and control variables

My questions are:
1. From the graph above, the highest point to plot on Z-axis is 11.67. Since my variables are all measured on 6-point Likert-type scale, is this abnormal?
2. What does high constant value imply? I did double check my SPSS syntax and every step of the progress, yet still unable to get any insight
3. Is there any special way to deal with control variables in Polynomial Regression? The way I do it is just adding them with independent variables

I urgently need answers for these. Please help.
]]>Psychology Statisticsangelove114http://www.talkstats.com/showthread.php/69048-Need-help-in-Polynomial-Regression-constant-value-and-control-variables