Variables

• Co-variables are measurements that have been made to compare to see if they are associated.

  • Correlation study = Direction and strength of the relationship between two co-variables can be describes ad positive or negative.
• In experimental studies, variables must be operationalised which states exactly what the variable is and how it is to be measured.
• Extraneous variables are any variable aside from the IV that could influence the measurement of the dependent variable. This could cause errors, potentially showing a false relationship between the IV and DV.
• Types of extraneous variables:

  • Demand characteristics - Altering of the participants behaviour to match the aim.
  • Participant variables - Participants have relevant characteristics, prior knowledge or skills related to the task in one condition, resulting in a difference in performance between conditions.
  • Situational variables - Environmental factors present in one condition and not the other (eg noise, temperature or visual differences).
  • Order effects - Differences in performance due to practice or fatigue.
• Confounding variables are variables that influence the relationship between the IV and DV (eg age).
• Controlling extraneous variables:

  • Demand characteristics - Single and double blind trails. In a single-blind trail, participant is blind to aims of the study, in double-blind trail both participant and researcher know the aims of the study. This is an attempt to stop the researcher from influencing the participants behaviour with their body language / tone.
  • Participant variables - Random allocation removes the potential bias in assigning more participants with relative characteristics.
  • Situational variables - Standardised procedures.
  • Order effects - Counter balancing (ABBA).
• Pilot studies use a small scale of the main research conducted before using the main study. This uses the same methodology, data collection and data analysis.
• Pilot studies aim to improve the quality of the main research by assessing the experience of participants. It can reveal:

  • Unexpected variables that need to be controlled.
  • Instructions, tasks or interview questions that may be confusing.
  • Participants may reveal they discovered the true aims of the study.
  • Researcher may find conducting the study is time-consuming and it's current set up may need to alter the standardised procedure or tasks.
  • In an observation, it may be clear the behavioural categories are not fully operationalised.
• Peer review is when the researcher shows their written up study to other experts in their field. As a part of the peer review process, unaccounted for variables may be identified to have confounded the results. This may mean the study lacks internal validity and will need to be repeated.