Introduction to T-Tests

Question 1

what is the research design looking for?

Answer 1

relationships or differences

Question 2

what is the level of data being used?

Answer 2

nominal, ordinal, interval, ratio

Question 3

what experimental group is being used?

Answer 3

repeated measures or independent groups

Question 4

is data normally distributed?

Answer 4

parametric or non-parametric

Question 5

what are t-tests?

Answer 5

tests that compare two means, and involve two groups (or one group and a population) to look at differences between them

Question 6

types of t-tests

Answer 6

1. unrelated/independent/between groups
2. related/dependent/paired sample/within groups/repeated measures

Question 7

what do t-tests require?

Answer 7

interval/ratio data, and must be normally distributed

require independent scores and homogeneity of variance

Question 8

how to explore data

Answer 8

1. assume the null hypothesis is true
2. plot distribution formed by all the difference means from the two populations
3. this obtains the sampling distribution of the difference between means

Question 9

what do t-tests relate?

Answer 9

the difference between the mean to the sample distribution

Question 10

what does the probability estimate tell?

Answer 10

whether our difference falls within the 5% of difference

Question 11

what is generated by SPSS?

Answer 11

a t-statistic that explains how many standard deviations our difference is

Question 12

what do descriptive statistics provide?

Answer 12

the mean value and standard deviation

Question 13

what does SPSS provide?

Answer 13

the t-statistic, degrees of freedom, p-statistic, and mean difference

Question 14

example of t-test being reported

Answer 14

t(9) = 5.131, p=0.001