# Search results

1. ### Variability instead of means?

Thank you for feedback. Well, I do see your point. I thought SD might (like variance) necessarily be not normal. I think we can say that any distribution of variances would not be normally distributed (as it is always positive, and we square to get there), so thought this might also be true for...
2. ### Variability instead of means?

I think it is relevant because if I were to do a t-test (or ANOVA in a more complex scenario) to compare pre/post then this requires normality. Means might be fine, but when I was thinking on this, the variance cannot be normal, and I am not sure if the SD would be either.
3. ### Variability instead of means?

Thank you for the idea. If I aggregate and end up with the SD can this be analyzed as if we are just analyzing the mean? e.g. t-test, ANOVA, so on. Or is this a violation of normality? I mean is the population standard DEV assumed to be a normal distribution? It feels a bit strange to think...
4. ### Variability instead of means?

Hello, I was thinking about analysing variability instead of means but could not find much for an answer. I am interested in learning more about this so I would appreciate some feedback. I made some R code to demonstrate my question (I can't code well in R, improvements are much welcome too)...
5. ### Within-Subjects ANOVA with low sample

Hello, I have some data that I want to analyse. It is 2x2 within-subjects design. My DV is continuous and the two factors have 2 categorical levels. But I only have 8 subjects, so I am unsure about how to proceed. Is it correct that there is no reasonable alternative to just using an ANOVA? If...
6. ### 3 way ANOVA following it up

This is quite simple question but im more simple :p I have DV and 3 IVs, each 2 levs. Making up example, lets say they are: DV=performance%, IV1=trial type (seeing, hearing) IV2=item type (target, distractor) IV3=confidence (high, low) Subjected to a 2x2x2 RM ANOVA in SPSS and i see no 3 way...
7. ### formula for factorial ANOVA interaction effect

Good day. I have a question regarding the formula for calculating interaction effects. In Andy Field book he gives: SSa×b = SSmodel − SSa − SSb, where a and b are the different factors in our model. What happens when we have 3 or more factors? Is this then: SSa×b×c = SSmodel - SSa - SSb - SSc...
8. ### p values, alpha, and errors

Thank you all for discussion, it has been very helpful!
9. ### p values, alpha, and errors

I mistyped this, it should be as quoted now. By "doesn't exceed" I meant p < .05. I think it's beginning to make sense. The p value is a probability of obtaining result of at least the detected size, given that the null is true. It doesn't say anything about error because there is not yet an...
10. ### Good day

I don't really know how to describe the context for signal detection, other than applying signal detection models to data collected in psychology experiments, and using SDT to better understand human perception for example. Of course it would be useful to learn how this is applied in other...
11. ### Good day

I know the feeling, I always feel like I have so much to learn in so little time :D It is a healthy pursuit at least. Frequentist statistics are used most frequently ( :cool: )in my field of study, so it is my main goal to learn as much of this as I can. If I can do this it would be nice to...
12. ### p values, alpha, and errors

Hmm I think it's starting to clear up, but I'm still uncertain about some things. So if we had p=.04 for example, then would we state that there is 96% chance that if you replicated the study you would observe an effect of at least this? OR in other words (for simplicity), if we ran the study...
13. ### Good day

Hi talkstats memebers! I am Alex. I study Psychology and I want to learn as much as I can about statistics.
14. ### p values, alpha, and errors

I was speaking with a classmate about subject heading for this thread and it made me a bit confused. Here are my thoughts: the way I explain p value: probability of observing effect when, in reality, there is no effect. This translates to probability of data given the null (null=there is no...