independent t test + null hypothesis Flashcards
hypothesis =
prediction to be tested in a research study
what 2 type of studies are used to test relationship between variables?
correlational study and categorical study
what are the 2 approaches to time?
cross-sectional or longitudinal
differences between groups will always have a ______ DV and a ______ IV
continuous, categorical
what are the 2 designs used with a differences between groups question?
between participants and within participants
what statistical test is used for a between participants design?
independent t-test
what statistical test is used for a within participants design?
paired t-test
what are the 2 statistical tests used for a relationship between variables question?
person’s correlation and person’s chi-square
what are the 2 statistical tests used for a differences between groups question?
independent t-test and paired t-test
continuous + continuous = what statistical test?
person’s correlation
categorical + categorical = what statistical test?
Pearson’s chi-square
what is the difference between an independent and paired t-test?
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
what is the aim of null hypothesis testing?
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
why will the sample mean unlikely be the same as the population mean?
sampling error and unsystematic variation
p value =
probability of finding an effect in the sample if there is no effect in the population
when is the p value small enough to reject the null hypothesis?
less than .05 (less than 5% chance)
we believe there is a significant effect in the population
p value gives us an indication of ______ ________
statistical significance.
effect sizes also indicate towards a significance and impact
the calculation of the p value is based on the calculation of the _ value
t
if mean difference increases, then t value ______ and p value _______
increases, decreases
identify the assumptions that need to be met in order to use an independent t-test analysis
data is approx. normally distributed, no clear outliers, the spread of scores (variance) need to be relatively equal in both groups
if data is not normally distributed what do you do?
use parametric test
