stats psych

retain the H0(null hypothesis)

f the p-value is smaller than α (e.g., p<.05). When you reject H0​, the result is called statistically significant

reject the H0 (null Hypothesis)

Retain H0​: If the p-value is greater than α (e.g., p>.05). This suggests there is not enough evidence to show the null hypothesis is false

The critical value acts as the boundary for the

rejection area

null hypothesis

The default assumption that nothing is going on there is that there is no difference, effect, or relationship in the population.

the hypothesis we test

Null Hypotesis (Ho)

Alternative Hypothesis (H1)

The prediction informed by your research. it states that a difference or effect does exist

P-value

The probability of obtaining your sample results (or more extreme results) assuming the null hypothesis is true

significance level (a)

the pre-determined threshold (usually 0.05) used to decide whether to reject the H0

Type I Error

Rejecting the null hypothesis when it is actually true (a "false positive

Type II

Retaining the null hypothesis when it is actually false (a "miss")

Chi-Square Goodness of Fit Test

used to assess a single categorical variable against a null hypothesis of equal frequencies across categories

degrees of freedom (df)

For a goodness of fit test, the formula is df=C−1, where C is the number of categories

expected frequency (E)

The count you would expect in each category if H0​ were true; calculated as Total Sample Size (N)/Number of Categories (C)

Chi-Square formula

χ2=∑(O−E)2​ /2

what is the purpose of a one sample t test

to compare a sample mean to a known population mean

which measure is commonly used to assess the difference between two means in units of standard deviations

chens d

in the context of effect size, what does cohens d measure

the magnitude of the difference between to means

what is another name for paired samples t test

related sample t test

what is the primary objective when performing a related samples t test

to analyse the change over time or the difference between two related assessments

formula to see how a change or different score calculated for a participant measured at two time points

x diff = xt2 - xt1

what is the formula to find degrees of freedom

N-1

what is the significance level of greek letter a

the criterion set for rejecting the null hypothesis

in a two sided test, where are the rejection regions located on the t distribution

both sides of the distribution