Year 1

• What is the experimental method?

  • The manipulation of an independent variable to measure the effect on the dependent variable in an experiment
• What is an aim?

  • A general statement of what the researcher intends to investigate outlining the purpose of the study
  • e.g. To investigate whether drinking energy drinks makes people more talkative
• What is a hypothesis?

  • A statement made at the start of a study that clearly describes the relationship between variables as stated by the theory
  • e.g. Drinking energy drinks causes people to become more talkative
• What are the types of hypothesis?

  • Directional hypothesis - states the direction of the difference or relationship e.g. people who drink energy drinks become more talkative than people who don't
  • Non-directional hypothesis - simply states that there is a difference between conditions but doesn't specify the nature of the difference e.g. people who drink energy drinks will differ in terms of talkativeness compared with people who don't drink energy drinks
• What is an independent variable?

  • An aspect of the experiment that is manipulated by the researcher or changes naturally so the effect on the dependent variable can be measured
• What is a dependent variable?

  • The variable that is being measured by the researcher - any effects on this should be caused by the change in IV
  • e.g. the amount of time a student studies should be an independent variable, and their test scores should be a dependent variable
• What are levels of the independent variable?

  • To test the IV's effect we need different experimental conditions to compare results, such as a control condition
  • e.g. comparing those who drink energy drinks with those who drink water
  • Directional hypothesis would be -> the group that drinks an energy drink will be chattier than the group that drinks water
• What is operationalisation of variables?

  • Defining abstract concepts or variables in a way that they can be measured and observed
  • Means turning theoretical ideas into concrete, measurable observations which ensures that the researcher can systematically collect data and analyse the concept in a way that is clear, objective, and replicable
  • e.g. after drinking 300ml of energy drink, participants say more words in the next 5 minutes than participants who drink 300ml of water
• What are extraneous variables?

  • Any variable other than the independent variable that may affect the dependent variable
  • Unwanted, should be controlled or removed or identified at the start of the study so the researcher can take steps to minimise their influence
  • Can include participants age, lighting in the lab, etc.
• What are confounding variables?

  • A type of extraneous variable that varies systematically with the independent variable, meaning we cannot establish a cause-and-effect between the IV and effects on the DV
  • e.g. participants in the first condition arrive extra excited as they saw a celebrity on their way, and the second group of participants are less excited meaning we cannot establish that their chattiness was due to the energy drink or their pre-existing excitement
• What are demand characteristics?

  • Any cues in a research setting that may be interpreted by the participants as revealing the purpose of an investigation
  • This may lead to participants altering their behaviour or responses to please the experimenter, known as the please-U effect
  • Means participant behaviour is no longer natural, acting as an extraneous variable that may affect the DV
• What are investigator effects?

  • Any unwanted influence of the investigator on the research outcome, including expectancy effects and actions of the researcher related to the study's design such as selection of participants, instructions, leading questions, etc.
  • For example, if we as a researcher expect the energy drink group to speak more, we may encourage a greater level of chattiness from them in our unconscious behaviour
• What is randomisation?

  • The use of chance methods to reduce the researcher's unconscious biases when designing an investigation
  • e.g. if ppts. recall words from a list in a memory experiment, the order of the list should be randomly generated to the researcher doesn't decide the position of each word
• What is standardisation?

  • As far as possible, all participants should be subject to the same environment, information, and experience
  • Means using exactly the same formalised procedures and instructions for all participants in a research study, such as standardised instructions
• What are other types of extraneous variables?

  • Participant variables are individual differences between participants that may affect the DV
  • Situational variables are any features of the experimental situation that may affect the DV
• What is an experimental design?

  • The different ways in which participants can be organised in relation to the experimental conditions
• What are independent groups?

  • When two separate groups of participants experience two different conditions of the experiment - if there are 2 levels of the independent variable then all participants experience 1 level only
  • e.g. one group would drink the energy drink and another group would drink water
  • Performance of both groups would be compared
• What are the strengths and limitations of independent groups?

  • Order effects are not a problem like they are for repeated measures and participants are much less likely to guess the aims
  • Participant variables are an issue - if there is a mean difference between groups it may be to do with individual differences which can act as a confounding variable, reducing the validity of the findings
  • Less economical than repeated measures as 2x as many participants are needed, increasing time/money spent on recruiting participants
• What is random allocation?

  • An attempt to control for participant variables in an independent groups design by ensuring each participant has the same chance of being in one condition as any other
  • Involves online random generation, pieces of paper with A or B written and placed in a hat for researcher to select randomly assigning participants to a group
• What are repeated measures?

  • When all participants experience both conditions of the experiment, for example experiencing condition A and then later be tested again in condition B
  • Two mean scores from both conditions would be compared to see if there was a difference
• What are the strengths and limitations of repeated measures?

  • Participant variables are controlled meaning there is higher validity and few participants are needed meaning less time/money spent recruiting them
  • Order effects - the impact of the sequence in which stimuli or conditions are presented on participants' responses, influencing how they answer or behave
  • Repeating 2 tasks may create boredom or fatigue that could cause deterioration, or performance may improve through the effects of practice like on skill-based tasks, meaning order acts as a confounding variable
  • Demand characteristics are also an issue as ppts. are likely to work out the aims of the experiment by experiencing all conditions
• What is counterbalancing?

  • An attempt to control order effects by having half the participants take part in condition A and then B, and have the other half take part in condition B then A, sometimes referred to as the ABBA technique
  • Attempts to balance out effects but may not remove or prevent the problem
• What is a matched pairs design?

  • Participants are paired together based on participant variables or variables relevant to the experiment such as IQ
  • One participant from each pair would be allocated to a different condition of the experiment, attempting to control for confounding and participant variables
  • e.g. out of the two chattiest people, one would be allocated to condition A and the other in condition B
• What are strengths and limitations of the matched pairs design?

  • Participants only experience a single condition meaning order effects and demand characteristics are less of a problem
  • Despite the attempt to reduce participant variables, ppts. can never be matched exactly meaning there will inevitably be differences that can affect the DV
  • Matching is time-consuming and expensive meaning this is less economical than other designs
• What is a laboratory experiment?

  • Conducted in highly controlled environments within which the researcher manipulates the IV and records the effect on the DV, maintaining strict control of extraneous variables
• What are the strengths of laboratory experiments?

  • High control over confounding and extraneous variables meaning any effect on the DV is likely to be caused by the IV, increasing internal validity
  • Replication is more possible, ensuring new extraneous variables are not introduced and thus increasing validity reliability
• What are the limitations of laboratory experiments?

  • May lack generalisability as the artificial lab environment is not like everyday life - participants may behave unusually in an unfamiliar context so their behaviour can't be generalised beyond the research setting (low external validity)
  • Ppts. are more aware they are being tested when in a lab, increasing unnatural behaviour as a result of demand characteristics
  • Low mundane realism as the tasks they are asked to perform may not represent everyday experience
• What is a field experiment?

  • Takes place in a natural, more everyday setting where the researcher goes to the participants' usual environment
• What are strengths of field experiments?

  • Higher mundane realism as the environment is more natural, meaning they may produce behaviour that is more valid and authentic
  • Participants may also be unaware they are being studies, increasing external validity
• What are limitations of field experiments?

  • Loss of control of confounding and extraneous variables, meaning cause and effect between IV and DV may be much more difficult to establish
  • Precise replication is often not possible
  • Important ethical issues as if ppts. are unaware they are being studies they cannot consent, which may be constitued as an invasion of privacy
• What is a natural experiment?

  • Where the researcher has no control over the independent variable and cannot change it, for example a natural disaster or whether a child is in hospital at age 5 or 10
  • The IV is natural not the setting - the DV may also be naturally occurring like exam results
• What are the strengths of natural experiments?

  • Provide opportunities for research that may not otherwise be undertaken for practical or ethical reasons such as the studies of institutionalised Romanian orphans
  • High external validity as they involve the study of real-world issues and problems as they happen
• What are the limitations of natural experiments?

  • Naturally occurring events are rare, reducing opportunities for research and can limit the scope for generalising findings to other similar situations
  • Ppts. may not be randomly allocated to experimental conditions, researcher is less sure whether the IV affected the DV
  • Research may be conducted in labs which lack realism and produce the issue of demand characteristics
• What are quasi-experiments?

  • A study with an independent variable that is based on an existing difference between people like age or gender, which is not manipulated and cannot be changed
  • DV may also be naturally occurring or may be devised by the experimenter and measured in a field or lab
• What are the strengths and limitations of quasi-experiments?

  • Often carried out under controlled conditions and share some strengths of a lab experiment
  • Cannot randomly allocate participants to conditions meaning there may be confounding variables that affect results
  • IV is not deliberately changed so we cannot claim that it actually caused any observed change
• What is the difference between a population and a sample?

  • Population is the large group of individuals a researcher is interested in studying, often called the target population
  • Samples are smaller groups that are representative of the target population to make generalisation possible, but lots of samples contain vias
• What is random sampling?

  • When all members of the target population have the same equal chance of being selected
  • Steps include obtaining a complete list of all members of the target pop, assigning them a number, and using a sort of lottery method to select them such as computer randomisers or picking numbers from a hat
• What are the strengths and limitations of random sampling?

  • Potentially unbiased meaning confounding or extraneous variables are equally divided between groups, enhancing internal validity
  • Difficult and time-consuming to conduct and obtaining a complete of the target pop may be very hard to get
  • Samples can still be unrepresentative due to chance
  • Selected participants may refuse to take part
• What is systematic sampling?

  • When every nth member of the target population is selected e.g. every 3rd house on a street
  • Sampling frame is produced with a list of members from the target pop organised into a list
  • A system is nominated and can begin from a randomly determined start to reduce bias
• What are strengths and limitations of systematic sampling?

  • Objective method - once the selection system has been established the researcher has no influence over who is chosen meaning researcher bias is massively reduced
  • Time-consuming and participants may refuse to take part