Variables

Recap from last lesson  Aims  Hypotheses  IV and DV

Eye on the Exam  A psychologist carried out an experiment using an independent groups design. The psychologist wished to investigate the effectiveness of a strategy for memory improvement. In one condition, participants were taught a memory improvement strategy. In the other condition, participants were not taught this memory improvement strategy. All participants were asked to memorise 10 pictures of familiar objects. For example, the first was a doll, the second was an apple. All participants were then given 50 pictures each, and asked to select the original 10.  Write a directional hypothesis for this experiment (2 marks)

Eye on the Exam A researcher investigated whether memory for words presented with pictures was better than memory for words presented without pictures. The researcher used an independent groups design. In Condition 1, participants were given a limited time to learn a list of 20 words. They were then asked to recall the 20 words in any order. In Condition 2, participants were given the same time to learn the same 20 words, but this time each word was presented with a picture. For example, the word ‘apple’ was presented alongside a picture of an apple. They were then asked to recall the 20 words in any order. State a non-directional hypothesis for this experiment (2 marks)

Eye on the Exam A psychologist used an independent groups design to investigate whether or not a cognitive interview was more effective than a standard interview, in recalling information. For this experiment, participants were recruited from an advertisement placed in a local paper. The advertisement informed the participants that they would be watching a film of a violent crime and that they would be interviewed about the content by a male police officer. The psychologist compared the mean number of items recalled in the cognitive interview with the mean number recalled in the standard interview. Identify the independent variable and the dependent variable in this experiment (2 marks)

Eye on the Exam Dave, a middle-aged male researcher, approached an adult in a busy street. He asked the adult for directions to the train station. He repeated this with 29 other adults. Each of the 30 adults was then approached by a second researcher, called Sam, who showed each of them 10 photographs of different middle-aged men, including a photograph of Dave. Sam asked the 30 adults to choose the photograph of the person who had asked them for directions to the train station. Sam estimated the age of each of the 30 adults and recorded whether each one had correctly chosen the photograph of Dave. Identify one aim of this experiment (2 marks).

Learning Objectives  To define operationalising of variables  To operationalise given variables  To define and give examples of extraneous variables

Variables  IV and DV  Extraneous Variables  Operationalising Variables

Operationalising Variables  Narrowing down the research focus  How the variables will be measured  For example, in a study looking at whether eating spinach increases strength, we could operationalise strength by measuring….

Your Task  Complete the page in your booklet to operationalise the given variables

Extraneous Variables other than affect  Anything other than the independent variable that could affect the dependent variable  Need to be controlled  Split into random errors and constant errors

Random Errors  Participant’s state of mind  Participant’s level of motivation  Incidental noise  Room temperature  Time of day  Previous experiences on the day of the study, for example…  Control for them by… allocating p’s randomly to the experimental conditions – random errors should balance out across the conditions

Constant Errors  A failure to randomise experimental conditions  Participant differences – i.e. gender, intelligence, age etc…  Errors of measurement which affect one condition more than another.

Your task  Complete the section on extraneous variables in your booklet

Eye on the Exam Dave, a middle-aged male researcher, approached an adult in a busy street. He asked the adult for directions to the train station. He repeated this with 29 other adults. Each of the 30 adults was then approached by a second researcher, called Sam, who showed each of them 10 photographs of different middle-aged men, including a photograph of Dave. Sam asked the 30 adults to choose the photograph of the person who had asked them for directions to the train station. Sam estimated the age of each of the 30 adults and recorded whether each one had correctly chosen the photograph of Dave  Identify one possible extraneous variable in this experiment. Explain how this extraneous variable could have affected the results of this experiment (4 marks).

Extension  Complete the first set of summary questions in your booklet (excluding those on ethical issues – we’ll look at them another time)  Ensure your booklet is up to date – use a textbook to help you