PSYC 217 Midterm #2

Experimenter Expectancy Effect + solutions

ex. Clever Hans (the horse that could do math)

A cognitive bias that occurs when a researcher knows what condition participants are in and therefore intentionally or unintentionally manipulates an experiment, thus impacting the findings.

• Experimenter treated participants/data differently because they knew the expected outcome of the study

• threat to internal validity

another ex. maze bright / maze dull rats → when a group of grad students are told this group of rats is smart/dumber they’ll treat them in a way that’ll result in that

Solutions:

1. a “double blind” study - experimenter & participant doesn’t know which one is which condition

2. automated instructions (ex. instructions are written down & shown)

3. all conditions run simultaneously - all participants are given the conditions and asked to start at same time

Demand Characteristics

• any feature of an experiment that might inform participants of the purpose of the study

• threat to internal validity

Participants might try to help/hurt you (we want ppl to behave naturally)

• Be the “good participant” (behave how they think the researcher wants them to behave)

• Mess up the results (purposely do smtg they normally wouldn’t do to harm the study)

• Social desirability (i don’t want researchers to think Im a certain way and so I hide that part of myself)

Deception

Often, we deceive subjects about the real purpose of a study

• “unrelated tasks” (filler tasks - make them do things that have nothing to do with it)

• use of confederates or cover story (smn on research team that is pretending to be a participant

  • solomon asch studies (line study)

  • milgram’s obedience study ( learner, teacher, shocks)

• attempt to avoid demand characteristics

→ not minimal risk

→ participants can get suspicious

→ *critical to debrief after study is finished

Straightforward Manipulation (of IV)

Simple & easy:

• just present participants with something for the IV (ex. writing, pictures, video, etc) that might influence the DV

  • no deception

ex. manipulate mood with music, a video, etc

Staged Manipulation

• Trying to indirectly elicit a state

ex. elicit frustration by giving people an impossible task

ex. elicit anger by having confederate insult a participant

Measuring Variables

• Variables of interest in correlational designs

• DV in experimental designs

1. Self-report - asking ppl about their attitudes/feelings

2. Behaviours & Responses - can measure how often ppl are drinking, their reaction times, etc

3. Physiological - HR, pupil dilation, BP, etc

Ceiling & Floor Effects

Ceiling Effects:

• all participants are at maximum performance so even if the IV causes differences in the DV, the groups don’t look any different → you can’t tell if there’s an effect of the IV on the DV

ex. trying to see if music effects math test results but all the questions are smtg like 1+1

Floor Effects:

• Participants are all at minimum performance on DV, so you can’t see an effect of the IV on the DV

ex. trying to see if music effects math test results but all the questions are calculus and the participants are middle schoolers

Strength of IV

• Strong manipulation - can cause big changes in DV

  • ex. DV = sense of self-efficacy

    • you were rejected by all the universities you applied to ! vs you won 4-year scholarships to every university you applied to

• weak manipulation - may cause small changes in DV

  • good at making fine distinctions in DVs, but usually can’t create big effects

    • ex. DV = sense of self-efficacy

      • you got a B+ in PSYC218 vs you got a C- in PSYC 218

  • better to use repeated measures when using this because there’s more room for error when using weak (repeated removes systematic error)

    • there’s more room for error because the variability is larger

Sensitivity of DV

• tough - something that won’t likely change

  • ex. views on political leaders

• sensitive - more sensitive to whatever the manipulation might be

  • ex. should Mark Carney be re-elected as Canada’s PM? 1 to 10, disagree to agree

ex. your spouse forgot to buy milk

• tough - would you divorce your spouse yes or no

• sensitive - how would you rate your level of marital satisfaction 1-10

Which to use? (strength of IVs & Sensitivity of DVs)

• when you dk anything about relationship its best to use strong IV & sensitive DV

• use a tough DV when you know its going to be hard to change

Survey Research Basics

You might need to ask your participants some questions

• to analyze & understand trends

• for correlational research

• as the DV in an experiment

• as a manipulation check in an experiment

you have to consider:

What questions will you ask and how will you word them? How will participants respond? Do you know?

• important to proofread and pilot the questions

What questions will you ask (in a survey) ?

What kind of information might you need to find out from participants?

• attitudes and beliefs

• facts and demographics

• behavioural frequencies

How will participants respond? (survey questions)

Question Wording Considerations (Survey Questions)

• Simplicity - avoid jargon, abbreviations, complexity

  • should VCHA increase expenditures to prevent myocardial infarctions?

• Avoid Double-barrelled questions

  • do you support free tuition and reduced healthcare?

  • do you feel anxious and depressed when thinking about exams?

• Avoid Loaded questions

  • are you in favour of having your terrific instructor Mark Lam teach another term of fun-filled 217?

• Avoid negative wording

  • do you agree that the City of Vancouver should not allow the homeless to camp on the streets?

Response sets (survey questions)

• additional considerations to making surveys

• a tendency to respond to all questions from a particular perspective or in a particular way rather than to provide answers to the questions themselves

solution:

• use answer checks “if you’re reading this answer 4”

• ask questions about the opposite

  • ex. survey on extraversion, ask questions like “how talkative are u” while also asking “how shy are u?'“

Social desirability (“faking good”) - Survey questions

• additional considerations to making surveys

• tendency for a participant to respond in the most socially acceptable way, or as “most ppl” would

• more likely with sensitive topics

Open-ended questions (survey)

• additional considerations to making surveys

• open-ended vs close-ended

• ex. tell me about your study habits. VS On avg how much time do you spend studying each week? (multiple choice)

Pros;

• can get rich, creative, unexpected, and/or complex answers

• identify common themes

cons:

• responses may be ambiguous

• participants may interpret questions in different ways

• time-consuming to code