# t-test

1. ### Selecting of statistical test?

I have a study whereby I asked two groups of participants (Clients (N=76) and Professionals (N=62) what qualities would make a treatment interaction positive and what qualities would make a treatment interaction negative. As part of my analysis I have totalled: - the number of positive...
2. ### ANOVA or T-test

Hi I have two categorical variables as in below example: Region Dim Value PK Dim1 2 PK Dim2 3 PK Dim3 -1 PK Dim4 -4 US Dim1 -0.5 US Dim2 4.3 US Dim3 2.1 US Dim4 2 PK Dim1 5 PK Dim2 -0.4 PK Dim3 -0.3 PK Dim4 0.8 US Dim1 1 US Dim2 2 US Dim3 0.8 US Dim4 1 I want to compare the variables US and PK...
3. ### Which statistical tests are appropriate: Group means before and after treatment

I am trying to find out what statistical tests to run on a set of aggregate data (no individual data) on 3 different groups, variables are summarized below: Group 1 in site 1: Mean value (blood sugar) of the total sample before treatment, and mean value (blood sugar) of the same group after...
4. ### [SPSS - T-Test] - understanding how to approach a question

Hello, I have I inputted my data into SPSS. This is the question that I have been given: Compare the QABF attention(interval data)scores and demand(interval data) scores of people with a diagnosis of FXS and those with any diagnosis. Are people with FXS more likely to have lower...
5. ### ANOVA or t-test?

I want to test 2 different treatments (diets), repeating each treatment 3 times on 25 individuals independent samples. After each repetition, four variables are measured on the individuals (weight, size, variable3, variable4) all quantitative. I want to assess the differences between the...
6. ### What would be the appropriate statistical tool?

Dear all, I am a graduate researcher in the analysis phase of my research work. My research is an intervention research (n=14) trying to analyze the impact (pre and post) of the sports program. I don’t have a control group for this research. My dependent variables fall under ordinal, likert and...
7. ### t-test or z-test for two proportions?

We did an intervention to reduce the frequency of use of a certain type of treatment and now I want to compare the data pre vs post intervention. For each month I have the number of treatments per 1000 patient visits (because the monthly number of visits fluctuates). I have 6 months of...
8. ### Before/After- t-test???

Hello everyone, Kinda new to this forum. I need help in finishing off this project. So, my research question is whether an increase in the blood alcohol content (i.e., drinking alcohol) lead to a decrease in the mental capacity of performing basic tasks. In order to perform this research (and...
9. ### Regression for comparing two groups on one variable? And t-test with survey data?

Hi - I have two populations / groups that I need to compare on one variable. Now usually I would use a t-test or anova but ive been told that these are unable to be used with survey data in stata. Is this correct advice - can I not use a t-test or anova in stata with survey data? And would a...
10. ### What kind of test should I use?

I have 50 test items for 1000 students, each student answered 30 of them. I would like to find out whether the rate of correctness of items is different for students in 3 programmes, further I want to group the items favourable for each programme. Items are scored by 0 (wrong), 1 (partially...
11. ### t-test for large sample size - bike hire data

Hello everyone, I'm taking a graduate-level statistics course at the University of Glasgow which includes a methods assignment. The assignment requires us to correctly execute several statistics, including one and two sample t tests. To complete my assignment, I'm using a large dataset...

Hi all I am working on a project looking at ADHD in a large sample of adolescents. I am looking to investigate whether there are any differences between those in my sample who have previously had a diagnosis of ADHD and those who have not, on various ADHD rating scales. The rating scales...
13. ### 1-sample binomial for my research data?

Hi, Newbie here so I will try to explain as clearly as I can. I do research in the neuro field. I have a control group of neurons that I am analyzing for the presence or absence (binary) of a specific trait (let's call it trait A). I found that the control group have A 60% of the time. Now I...
14. ### Help with homework

On a homework assignment, I have a data set with the variables (in SPSS) 1) Age 2) Reactiontime (continuous) 3) drug (Placebo, or drug condition) 4) Amount of drug metabolites in their blood (continuous) 5) Subject number (1-20) 6) A median split dichotomous variable on drug levels (0...
15. ### Likert Survey -- Stat for comparing single items and sub categories

Hello, For my dissertation I am using an existing 50 item Likert survey. I am pretty sure I will use a t-test to determine if there are differences between my two groups for the individual items. What I am not sure about....is the 50 items are divided into 7 subcategories....to determine...
16. ### Help deciding paired vs unpaired t-test

Hi, I am analyzing an experiment in which protein levels were examined in two different strains of bacteria. Lets call them A and B. Three separate times bacteria A and B were grown up and their protein levels measured. Would each day's samples now be paired since they were grown on the same...
17. ### Statistical Analysis of Student Test Scores before and after an Intervention

Hello, Please help me ensure that I am conducting the proper statistical analysis. I am trying to determine if my student test score results are statistically significant after having applied a learning intervention. The data I am using are student test scores on TEST 1 from my 3 previous...
18. ### Different degrees of freedom when reporting multiple T-tests

Please refer to Table attached. This study compares those without a phobic disorder (n=83) with those with a phobic disorder (n=16) on Temperament scores. What I am confused about, is the reporting of the degrees of freedom: shouldn't the degrees of freedom all be the same number (i.e., n -...
19. ### Pair t-test with non-independent samples

Dear list, In my experiment, each subject of my sample has three time-series of data: tc_A, tc_B and tc_C. Using Pearson correlation within subject I calculate correlations between time-series: tc_A vs. tc_B, tc_A vs. tc_C and tc_B vs. tc_C. So, for each subject I get three correlation values...
20. ### Beginner questions: Clinical trial

Hi there! I am a medical student working on my PhD, and I am analyzing some data for a meeting. Since we don't learn much about statistics (at least not here in Germany :D), I have some beginner questions and I would be extremely happy if you could help me. The first question is the most...