Research methods Factors affecting choice of statistical test, including levels of measurement

Appropriate selection of graphical representations Probability and significance, including the interpretation of significance and Type 1/Type 2 errors Factors affecting choice of statistical test, including levels of measurement The use of inferential analysis, including Spearman’s Rho, Mann- Whitney, Wilcoxon, Chi-Squared Analysis and interpretation of qualitative data Conventions of reporting on psychological investigations Data analysis and reporting on investigations

Levels of measurement Nominal data Categorical data use of a categorical classification system: ‘tall’ or ‘short’ Must be able to place each item or person in just one category for purpose of comparison e.g – male and female – Red, green and blue objects

Levels of measurement Ordinal data: Use ranks to order. Measure along a scale. Using a measured variable

Levels of measurement Interval data: Uses equal units (e.g. time) Measured differences between people Compare you to the general measure

A psychologist counts the number of males and females who are shopping on a Saturday morning in Churchill Square. A researcher measures how quickly participants can run 50 metres. A researcher asks participants to put ten photographs of faces in order from most to least attractive. A researcher asks five year olds what their favourite flavours of ice cream are. A psychologist measures the attachment style of children: secure or insecure. The social readjustment rating scale counts up the life change units assigned to the items that have happened to the participants in the previous two years.