chapter 5: inferential statistics

inferential statistics

conclude information from evidence and reasoning; allow to make conclusions from gathered data

descriptive stats

organize/describe data

hypothesis

statement of presumed relation btw at least 2 variables

null and alternative

population

entire group of people or observations in question

sample

a more specific subgroup of the population

null hypothesis

a statement that there WON’T BE an interaction btw variables following experiment

alternative hypothesis

a statement that there WILL BE an interaction btw variables following an experiment

research hypothesis

what the research believes will occur from experiment

independent variable

variable manipulated by researcher

dependent variable

the outcome measured by researched

type 1 error

reporting an interaction btw variables, when there actually ISN’T

type 2 error

reporting there isn’t an interaction btw variables, when there actually IS

significance

expressed as a p value

usually set at .05 or .01

a p value of .05 indicates that there is a 95% confidence the difference btw groups resulted from experiment, and not error or chance

purpose of experiment

determine if there is a difference btw groups from experiment, or by chance

T-test for independent groups

2 dependent variables being tested for one dependent variable

dependent t-test for paired groups

one group being tested twice on one dependent variable; pre-test and post-test

one-way ANOVA

more than two groups being tested once

two-way ANOVA

to measure the difference between 3+ groups when they interact with two independent variables