experimental

• What is meant by a 'research method' in Psychology?

  A technique for gathering data on the mind and behaviour.
• What makes an 'experiment' different from other research methods?

  It involves an IV and a DV.
• What is the independent variable?

  The variable in an experiment which is changed or manipulated.
• What is the dependent variable?

  The variable in an experiment which is measured, to see how it has been affected by the IV.
• What does it mean to 'operationalise' a variable?


  To make it specific and measurable.
• What is an extraneous variable?

  Variables, other than the IV, which could have an effect on the DV.
• What is meant by validity?

  Whether we are measuring what we inteded to measure.
• How can the presence of extraneous variables affect the validity of research?

  They can reduce the validity of findings, as they mean the experimenter is no longer measuring what they intended (no longer just the affect of the IV on the DV).
• What is the difference between situational variables and participant variables? (Types of extraneous variables)


  Situational variables are to do with the environment or situation. Participant variables are to do with differences between participants.
• What is meant by order effects?

  Whereby the order in which participants complete the different conditions of an experiment influence how they behave (this includes gaining practise, becoming tired or bored).
• What is meant by demand characteristics?

  When participants think they know the aim of the research and change their behaviour, acting in a way that they think the psychologist wants them to.
• What is meant by investigator effects?

  When the researcher unintentionally gives clues to participants about how they should behave, which then alters their behaviour.
• What is a standardised procedure?

  Where the procedure of a study is the same across all conditions, and for all participants.
• How does counterbalancing and randomisation work?

  Counterbalancing: where half of the participant group experience condition A then condition B, while the other half experience condition B then condition A. Randomisation: when participants are randomly assigned to condition A or B as their first or second test condition. Both control order effects.
• What's the difference between a single-blind and double-blind technique?

  Single-blind: when information about the study is withheld from participants (to prevent demand characteristics). Double-blind: when the aims of the study are withheld from both participants and researchers (also prevents investigator effects).
• What is a hypothesis?

  A statement of predicted outcomes based on a theory being tested.
• What is a null hypothesis?

  A prediction that the result or outcome will find no effect or very little effect.
• What is an alternative hypothesis?

  A prediction that the result or outcome will find a significant effect. It is known as an alternative hypothesis because it is 'alternative' to the null hypothesis.
• Write a null hypothesis for the follow investigation: Does age affect short-term memory?

  There will be no significant difference in the short-term memory ability (measured through their score on a digit span test) between older participants and younger participants. Any difference will be due to chance.
• Write an alternative hypothesis for the follow investigation: Do sweets have an impact on children's attention span?

  There will be a significant difference in the attention span (measured through time spent concentrating in a lesson) between children who it lots of sweets and children who eat few sweets.
• What is the 'target population'?

  The group of people being investigated, to which the findings will be generalised.
• What is the 'sample'?

  A selection of the target population that is directly studied in an investigation.
• Who are the 'participants'?


  The people who take part in a study.
• What does it mean for a sample to be 'representative'?

  Whether results of a study represent the whole population, not just the sample used.
• What does it mean if findings from a study are 'generalisable'?

  Extent to which results can be generalised to groups of people other than the sample.
• Describe 'random sampling' and give one strength AND weakness.

  Every member of the target pop. has equal chance of being selected. Every member given a no. which is placed in a hat and then a selection are drawn out at random. S: free from researcher bias - researcher has no influence on who is chose. W: difficult / costly to ensure every member of target pop. has equal chance of being selected.
• Describe 'stratified sampling' and give one strength AND weakness.

  Subgroups are identified within the target pop. Participants are obtained from each subgroup, using a random sampling method, in proportion to their occurrence in the target population. S: sample is likely to be representative as each subgroup within the target population will be represented. W: difficult / costly to ensure all subgroups in the target pop. are represented in the sample.
• Describe 'volunteer sampling' and give one strength AND weakness.

  Participants who are willing to volunteer themselves to take part in a study (often means advertising the study). S: minimal effort from researchers - quicker and easier than other methods. W: unlikely to produce a representative sample - not everyone will see the advert or want to respond.
• Describe 'opportunity sampling' and give one strength AND weakness.

  Selecting anyone who is available and willing to take part at the time. S: requires little effort from the researcher (so likely to be the cheapest method). W: biased sample likely to be produced, as not every member of the target population may be around at the time of the study.
• What is an experimental design?

  Refers to how participants are organised or allocated into the different conditions of a study.
• Describe an independent groups design.

  Involves multiple separate groups of participants completing only one condition of a study.
• Describe a repeated measures design.

  Involves the same participants completing both / all conditions of a study.
• Describe a matched pairs design.

  Involves two separate groups of participants completing only one condition of a study, yet these groups are matched on important characteristics, such as age or gender.
• What are 'order effects'? Which design are they a weakness of?

  Whereby the order in which participants complete the different conditions of an experiment influence how they behave (this includes gaining practise, becoming tired or bored). A weakness of repeated measures.
• What are 'individual differences'? Which design are they a weakness of?

  Differences between participants in different conditions of a study, which may affect their results. A problem with independent groups design.
• What are 'demand characteristics'? Which design are they a weakness of?

  When participants think they know the aim of the research and change their behaviour, acting in a way that they think the psychologist wants them to. A problem with a repeated measures design.
• What are 'ethical issues'?

  Codes or rules of conduct considered by psychologists when carrying out research to protect participants from harm.
• What does the following ethical issue refer to, and how can a researcher deal with it? Informed consent.

  The agreement of participants to take part in a study once they are fully aware of the aims. Researchers may ask for retrospective consent, asking participants if they happy to have their results included in the study after it has concluded, and they have been told the aims.
• What does the following ethical issue refer to, and how can a researcher deal with it? Deception.

  When participants are misled or lied to about the nature of the investigation. If participants are deceived, then a debrief should be held - a meeting after the study has ended, where participants are told the true aim of the research.
• What does the following ethical issue refer to, and how can a researcher deal with it? Right to withdraw.

  Participants should be aware that they are allowed to leave the study at any point. Participants should be reminded before, during, and after a study that they can leave.