All Questions
Tagged with statistics measurement
29
questions
2
votes
0
answers
33
views
Equating between short form and long form of the same instrument
I have encountered several instruments in psychology and related fields where we have multiple versions of the same instrument, specifically a short form and a long form. For instance, the patient ...
- 21
3
votes
1
answer
72
views
Best practice for comparing data between completers and non-completers?
I conducted a study which collected data on a brief one-time intervention at 3 timepoints (pre, post, and one-week follow-up). There were some participants who dropped out between these 3 timepoints. ...
- 31
1
vote
1
answer
35
views
Preregistration questions sample/outliers
HI I'm extremely new to research and my professor asked me to complete a preregistration for a project he wants to co author. However, I am stuck because the preregistration he asked me to complete ...
- 11
3
votes
1
answer
121
views
Using Exploratory Factor Analysis for Items That Belong to Different Scales
I have a quick question about factor analysis from different scales. Is it advisable to use, conjunctly, items from various measures? For example, say that I want to evaluate factors that most ...
- 31
0
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0
answers
497
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How to determine the sample size for a Confirmatory Factor Analysis CFA
I'm in the process of developing a scale. Overall, my question is how do I determine how many participants to include in my sample for the first Confirmatory Factor Analysis procedure? More ...
- 674
3
votes
0
answers
97
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Do different ethnic groups have the same standard deviation of the IQ distribution?
There is a lot of research suggesting that different ethnic groups either within US or worldwide if all plotted together would have distributions of IQ with different averages. The reasons for that ...
- 31
0
votes
1
answer
154
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Method and sample size to test validity and reliability of a scale/ survey
I am working on a project where I need to use a scale to measure certain psychological and political positions. I have a questionnaire that is used in the US, and whose validity was tested there quite ...
1
vote
0
answers
17
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Is Cronbach's alpha used outside of psychology?
Tau-equivalent reliability ($\rho$$T$), also known as Cronbach's alpha is a widely used measure of reliability in psychological testing. I've not encountered Cronbach's alpha in other sectors. Does ...
- 1,728
4
votes
0
answers
368
views
Calculating Significantly Above Chance for 3-AFC Test
I am trying to figure out which participants who took a 18-item multiple choice test scored significantly above chance. Each item has 3 choices, so the probability of getting each question correct is ...
3
votes
1
answer
67
views
Correlation used as explanatory device in ''The neuroscience of Intelligence'
I am currently reading Dr. Richard Haier's book The Neuroscience of Intelligence. I have a base knowledge of statistics, but I am confused about the following extract from page 80 (chapter 2.4):
...
- 33
1
vote
1
answer
28
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What is the notation about group differences in terms standard deviations?
I am just getting into watching psych lectures and things online and am taking notes but I have been wondering what the proper/standard way of writing in note form about standard deviations is.
For ...
- 11
0
votes
1
answer
80
views
What is the distinction between "relationship" and "difference" in behavioural statistics?
Quoting [emphasis added] from D.C. Howell's (2012) Statistical Methods for Psychology, chapter 9 (Correlation and Regression), Pg 252:
Although you should not make too much of the distinction ...
- 320
3
votes
2
answers
708
views
Bounds on skew and kurtosis of IQ
The question of whether IQ is Normally distributed, or instead follows e.g. a Pearson type IV distribution, has been debated since at least the 1910s. The quotient- and deviation-based definitions ...
- 201
4
votes
1
answer
1k
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What does it mean statistically for there to be significant differences in average IQ scores between racial groups?
Charles Murray (in his book, "The Bell Curve") reported that there are real differences between the mean IQ scores of different racial groups. He also points out that IQ variation within said groups ...
- 149
2
votes
1
answer
149
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What is restriction of range correction formula when you don't know standard deviation of unrestricted group?
What is the restriction of range formula if you don't know the standard deviation of the unrestricted group is?
For instance, you run a selection process, 1st stage is a cognitive ability test and ...
