# PS101 Lecture Notes - Lecture 3: Statistical Significance, Informed Consent, Research

## Document Summary

Descriptive research - no manipulation, the researcher just measures two variables: correlations indicate if there is a relationship between two variables. Experimental research - researcher manipulates a variable and compares performance across different groups. Inferential statistic indicate if the difference between groups is meaningful. Perfect positive correlation, all data points lie on line of best fit. Strong positive correlation, dots clustered around line of best fit. Near zero correlation, no evident line of best fit, correlation of 0. We can calculate the correlation coefficient "r" that tells you the strength of the relationship as a numerical representation of the relation between variables. It is represented as a relationship between - 1 and 1 where -1 and 1 are the strongest correlation. Experiments allow casual conclusions: uses inferential statistic to make inferences about data sets, conclude differences between groups are genuine and not due to chance, to do this, need to look at descriptive statistics.