Chapter 1: Science Skills and Research Methods

Question 1

Aim

Answer 1

• A statement outlining the purpose of the investigation
• E.g. the aim of this investigation is to compare differences in the amount of sleep obtained by adolescents and elderly people

Question 2

Hypothesis

Answer 2

• Testable prediction of relationship between 2/+ variables
• E.g. it is hypothesised that mobile phone conversations while driving, whether hands-on or hands-off, impairs driving performance

NOTE: There is no preferred writing style for a research hypothesis (nor is there a mandated style for VCE Psychology).

Question 3

Theories and models

Used interchangeably

Answer 3

• Interrelated concepts that attempt to explain observations and make predictions about future events

Question 4

Variables

Answer 4

• A variable is something that can change
• Independent – changed / manipulated
• Dependent – influenced by IV and is measured
• Controlled – considered to have an effect on DV and are thus kept constant to remove their potential effects (ensures that results are caused by changes in the IV)
• Extraneous – variable other than the IV that can cause a change in the DV (not controlled and have unwanted effects)
• Confounding – have systematic effects on the DV (make it impossible to know what has caused a change in DV)

Question 5

Population vs sample

Answer 5

• Population – entire group of interest from which the researcher draws a sample and seeks to generalise the results of their investigation
  
  • Members typically share characteristics (e.g. students)
• Sample – part of the population selected for research
  
  • Always smaller than a population
  • Should ideally accurately reflect entire population of interest

NOTE: The population is often referred to as the target population.

Question 6

Representative vs biased sample

Answer 6

• Representative – closely resembles the population from which it is drawn from
  
  • Sample has minimal errors in representing the population
  • Equal distribution of key participant characteristics
• Biased – does not adequately represent the key characteristics of its population

NOTE: Generally, the larger the sample, the more likely it is to be a representative.

Question 7

Sampling techniques

Answer 7

• Random – every member of the population is equally subject to being selected to be part of the sample
  
  • Poses minimal error in representing the population
• Stratified – sample consists of subgroups in the same proportion as they occur in the population of interest
  
  • Used to study behaviour / mental processes that tend to vary among different subgroups within a population
• Convenience – selecting members of the population that are easy to involve in the study
  
  • E.g. asking acquaintances or surveying people on the street

Question 8

Experimental and control groups

Answer 8

• Experimental – exposed to the independent variable
• Control – not exposed to the independent variable

Question 9

Random allocation

Answer 9

• Participants are equally as likely to be in one group as the other
• E.g. coin tossing or drawing names from a jar

Question 10

Between subjects (independent groups)

Experimental design

Answer 10

• Each participant is assigned to one group and provides only one piece of data
• Advantage – cost and time efficient
• Disadvantage – less control over participant differences

Question 11

Within subjects (repeated measures)

Answer 11

• Each participant is assigned to all groups and provides multiple pieces of data
• Advantage – individual participant differences can be controlled
• Disadvantages – performance can be influenced by fatigue or boredom (order effects)

Question 12

Mixed design

Answer 12

• Combines features of the between and within subjects design
• Advantage – takes advantage of the strengths of each design
• Disadvantage – limitations of both designs still exist

Question 13

Experimental vs non-experimental research methods

Answer 13

• Experimental
  
  • Laboratory experiments (within a lab)
  • Field experiments (natural and ‘real-world’)
• Non-experimental
  
  • Case studies
  • Observational studies
  • Questionnaires and interviews
  • Correlational studies
  • Simulation studies

Question 14

Correlational study

Answer 14

• Researchers observe and measure the relationship between variables without any active control or manipulation of them
• Used when not ethical / possible to experimentally manipulate the IV
• E.g. trauma, SA, drug misuse, age, gender

Question 15

Direction of correlation

Answer 15

• Positive – as one variable ↑, the other variable also ↑
• Negative – as one variable ↑, the other V ↓ (and vice versa)
• Zero – no relationship between the variables

Question 16

List and explain the types of uncontrolled variables

Answer 16

• Individual/participant differences: differences between participants which bias results
  
  • Control by using participants with similar characteristics such as age, gender and cognitive abilities
• Placebo effect: experimental group changes their behaviours due to placebo and not the experimental treatment
  
  • Control by giving control placebo (to raise baseline) or with a single blind method in which participants do not know their group
• Order effects: occurs in within-subjects whereby a participant’s performance is impacted by their participation in previous trials
  
  • Control with counterbalancing (groups do conditions in different, balanced orders)
• Experimenter effects: groups receive inconsistent treatment which produce biased results
  
  • Control with standardised procedures between experimenters or a double blind method whereby neither experimenter nor participants know their group
• Demand characteristics: individuals believe that they know the expected results of the study and consciously change their behaviour accordingly
  
  • Control with a single or double blind method
• Hawthorne effect: subjects change behaviour when knowing they’re being watched (common in observational studies)
  
  • Control with single or double blind
• Unstandardised instructions/methods
  
  • Control with scripts and standardised procedures

Question 17

Interpreting deviations

Answer 17

• Higher standard deviation = more varied data
• Lower standard deviation = less varied data

Question 18

Types of data

Answer 18

• Primary: collected first-hand by current researchers
• Secondary: collected earlier by different researchers
• Qualitative: non-numerical information (usually descriptions)
• Quantitative: numerical information
• Subjective: based on personal opinion
• Objective: measurable, verifiable and free from personal bias

Question 19

Positive and negative controls

Answer 19

• Positive control is a group that is exposed to experimental treatment that produces a known result
  
  • Used to confirm that the system is functioning correctly
• Negative control is a group that is not exposed to the experimental treatment
  
  • Provides a baseline for comparison
  • Used to identify and eliminate extraneous variables

Question 20

Repeatability and reproducibility

Answer 20

• Repeatability – how close measurements are to each other in identical conditions
  
  • Observer repeats experiment and produces same results
• Reproducibility – how close results are when the same variable is being measured under different conditions
  
  • Other people repeat experiment and produce same results

Question 21

Types of errors

Answer 21

• Random error – unpredictable (chance) variations in measurements that affect the precision of an experiment
• Systematic error – errors that are consistent and are due to fault in the method/equipment (affect the accuracy of a measurement and cannot be improved by repeating an experiment)
• Personal errors – mistakes made by the experimenter or researcher

Question 22

Research methods

Answer 22

• Experimental methods investigate what causes an outcome
• Correlational methods measure the relationship between variables
• Descriptive methods describe what is occuring
  
  • Observational studies (e.g. participant observations)
  • Self-reports (e.g. interviews, questionnaires)
  • Case studies (e.g. specific activities, behaviours, events or problems)

Question 23

Validity

Answer 23

• Internal – how successfully an experiment measures what it was intended to measure
• External – the extent to which research findings can be generalised to a greater population

Question 24

Ethical guidelines