Introduction to Experiments Types of Research Method l

Introduction to Experiments

Types of Research Method l A non-experimental method is one where no manipulation of variables takes place. The ones we will be looking at are – – Correlations Observations Questionnaires and interviews Case studies.

Types of Research Method l An experimental method is any research method where one variable is manipulated by the researcher, and the change on another variable is measured (the IV and the DV). The three that we will be looking at are: – – – Laboratory experiments Field experiments Natural/quasi experiments

YOUR TURN p 136 l l l l Define the following words using p 136 (leave a few lines after each for additions during feedback) Hypothesis Dependent Variable Operationalised Independent Variable Conditions Extraneous Variables

Lab Experiment l l l It takes place in a controlled, artificial setting. Standardised procedures are used The experimenter will be manipulating at lease one independent variable, and measuring at least one dependent variable. Therefore, there will be two or more conditions. The participants know that they are in a study, although, they may be deceived about its true aims.

Field Experiment • • More natural environment So, less control than lab experiment IV manipulated by experimenter Participants often don’t know they are in a study

Natural Experiment • • More natural environment IV NOT manipulated by experimenter – it occurs naturally

Lab studies l Think back to PY 1. Which of the studies we looked at were laboratory studies?

Experimental Designs p 137 l l Using the Blue Box on p 137 define and give examples of the following 3 experimental designs : Independent Measures Repeated Measures Matched Pairs

Strengths and weaknesses of lab studies l We will look at these in comparison to other types of experiment.