!!!*aims, hypotheses, variations

• definitions

  aim = idea about an interesting topic, usually broad area that must be narrowed down

  hypothesis = precise prediction about the expected findings of a study
• types of hypothesis

  experimental = predicts something will change

  null = predicts there will be no difference

  reuired IV and opeartionalised DV
• types of experimental hypothesis

  directional/one-tailed = required previous research, IV will influence specified changes in DV, confident which way the results will go

  non directional/two-tailed = doesnt require previous research, IV will influence changed in DV, not sure which way the results wil go
• null hypothesis - identifying and controlling variables

  IV = manipulated to observe DV effects

  DV = changes result of manipulation measures

  extraneous = all other variables that have an unwanted effect on DV
• confounding variables

  ?: variables not controlled during an experiment, identified afterwards

  • random error = unanticipated variable e.g., lack of sleep, pneumatic drill etc
  • constant error = consistently effects the DV e.g., instructions given etc (in addition to the IV)
  • participant error = related to participants e.g., individual differences, sampling etc
  • situational error = issues related to the setting e.g., time of day, room etc
• randomisation

  in place to reduce extraneous/confounding variables by using chance to reduce researcher influences

  done through randomly generating word lists or randomly allocating participants to a condition or sample
• ivestigator effects - their unconscious influence on results


  physical characteristics = age, gender (potential sexism), ethnicity

  other characteristics = tone of voice/accent can cause a subconscious bias - requires a double blind
• standardisation - makes the experiment the same for all participants


  requires a detailed and strict guide to be created on behaviour during the experiment e.g., how long they have for a certain task, script of what the researcher should say etc
• standardisation requirements

  • instructions, environment and information must be standarised
  • step-by-step procedure which can be repeated must be standardised for every participant
  • variations should not be confounding