independent t test + null hypothesis

Question 1

hypothesis =

Answer 1

prediction to be tested in a research study

Question 2

what 2 type of studies are used to test relationship between variables?

Answer 2

correlational study and categorical study

Question 3

what are the 2 approaches to time?

Answer 3

cross-sectional or longitudinal

Question 4

differences between groups will always have a ______ DV and a ______ IV

Answer 4

continuous, categorical

Question 5

what are the 2 designs used with a differences between groups question?

Answer 5

between participants and within participants

Question 6

what statistical test is used for a between participants design?

Answer 6

independent t-test

Question 7

what statistical test is used for a within participants design?

Answer 7

paired t-test

Question 8

what are the 2 statistical tests used for a relationship between variables question?

Answer 8

person’s correlation and person’s chi-square

Question 9

what are the 2 statistical tests used for a differences between groups question?

Answer 9

independent t-test and paired t-test

Question 10

continuous + continuous = what statistical test?

Answer 10

person’s correlation

Question 11

categorical + categorical = what statistical test?

Answer 11

Pearson’s chi-square

Question 12

what is the difference between an independent and paired t-test?

Answer 12

independent when using between participants and comparing the difference between the means of 2 independent groups.

paired t-test when using within participants and comparing the difference between the 2 means of the same group

Question 13

what is the aim of null hypothesis testing?

Answer 13

to falsify the idea that there is no effect in the population.

want to disprove the null hypothesis as it is impossible to prove systematic variation (H1) but we can disprove unsystematic variation.

we want the chance to be that there is no effect in the population to be as small as possible

Question 14

why will the sample mean unlikely be the same as the population mean?

Answer 14

sampling error and unsystematic variation

Question 15

p value =

Answer 15

probability of finding an effect in the sample if there is no effect in the population

Question 16

when is the p value small enough to reject the null hypothesis?

Answer 16

less than .05 (less than 5% chance)

we believe there is a significant effect in the population

Question 17

p value gives us an indication of ______ ________

Answer 17

statistical significance.

effect sizes also indicate towards a significance and impact

Question 18

the calculation of the p value is based on the calculation of the _ value

Answer 18

t

Question 19

if mean difference increases, then t value ______ and p value _______

Answer 19

increases, decreases

Question 20

identify the assumptions that need to be met in order to use an independent t-test analysis

Answer 20

data is approx. normally distributed, no clear outliers, the spread of scores (variance) need to be relatively equal in both groups

Question 21

if data is not normally distributed what do you do?

Answer 21

use parametric test