VCE Psychology: Research Methods - Mega Revision Notes

VCE Psychology: Research Methods - Mega Revision

Experiments, Variables, & Hypotheses

  • Psychology is a science employing the scientific method.
  • Scientific method: A systematic approach to planning, conducting, and reporting research.
  • Involves collecting empirical evidence.
  • Empirical evidence: Data collected directly from observation or experimentation.
  • Scientific method ensures accurate, reliable, and valid data.
Research Questions and Aims
  • Research questions: Ideas for scientific investigation phrased as questions.
    • E.g., Does sleep reduce with age? Does practice improve learning?
  • Aim: A statement of purpose for the investigation.
    • E.g., Compare differences in sleep between adolescents and the elderly. Assess the effects of practice on learning.
Experiments
  • Experiment: A controlled research study testing whether one variable influences another.
  • Tests cause-effect relationships between two factors.
  • The IV is manipulated; changes in the DV are attributed to the IV.
    • E.g., Does eating red meat cause more energy?
Simple Variables
  • Independent Variable (IV):
    • The variable the researcher manipulates to assess its effects on the DV.
  • Dependent Variable (DV):
    • The variable the researcher measures to assess the effects of the IV.
    • Changes in the DV result from manipulating the IV.
Examples of IV and DV
  • Eating a low-fat diet will improve physical health.
    • IV: Eating a low-fat diet
    • DV: Improved physical health
  • Students who exercise daily will have improved sleep quality.
    • IV: Exercising once a day
    • DV: Improved sleep quality
Operationalised Definitions
  • Operationalised Definitions refer to how variables are measured in research.
  • Exercise = 30 minutes of jogging/day
  • Depression = Number of negative words used in a creative story
Identifying and Operationalising IVs and DVs
  • Eating a low-fat diet will improve physical health.
    • IV: Eating a low-fat diet (Foods with less than 10% total fat)
    • DV: Improved physical health (Reduction in BMI)
  • Students who exercise once a day will sleep better.
    • IV: Exercise (30 minutes of jogging once a day)
    • DV: Quality of sleep (Amount of time spent in REM throughout the night)
  • Studying in the morning is more effective than studying in the evening.
    • IV: Time of study (morning or evening) - Operationalised IV: Studying from 8:00 – 9:00 am or studying from 6:00 – 7:00 pm
    • DV: Effectiveness of study - Operationalised DV: Amount of information retained
  • Children who want violent movies will be more aggressive than those who don’t watch violent movies.
    • IV: Watching violent movies or not - Operationalised IV: Watching movies rated R
    • DV: Level of aggression - Operationalised DV: Number of times the child hits other children
  • Eating bread crusts will give you curly hair.
    • IV: Eating bread crusts or not - Operationalised IV: Eating four bread crusts per day for one month
    • DV: Curly hair or not - Operationalised DV: Number of curls

Research Hypotheses

  • Research Hypothesis is a testable prediction of the relationship between two or more events or characteristics.
  • States the causal relationship between IV and DV (IV causes changes in DV).
  • Includes the population (people of interest) if provided.
Writing Hypotheses - Example
  • Does sleep deprivation cause memory problems in adolescents?
    • Step 1: Determine the IV and DV:
      • IV: Sleep deprivation
      • DV: Memory problems
    • Step 2: Decide on the direction (impact of IV on DV):
      • Direction: Sleep deprivation will cause memory problems.
    • Step 3: Identify the population (if outlined):
      • Population: Adolescents
    • Step 4: Write the research hypothesis:
      • “It is hypothesised that adolescents who are sleep deprived will have memory problems.”
    • Step 5: Include a comparison between experimental and control groups:
      • “It is hypothesised that adolescents who are sleep deprived will have more memory problems than adolescents who are not sleep deprived.”
Experimental and Control Groups
  • Control Group: Participants not exposed to the IV.
  • Experimental Group: Participants exposed to the IV.
  • Results of both groups are compared to determine the effect of the IV.
Memory Cue for Hypotheses (PIDD)
  • Population (if provided)
  • IV (include a comparison)
  • Direction
  • DV
Formula for Writing Research Hypotheses
  • “It is hypothesised that population who are exposed to the experimental group (IV) will have more DV than the control group (IV).”

Extraneous and Confounding Variables

  • Extraneous variables (EV): Variables other than the IV that may cause changes in the DV.
  • Affect the results of an experiment in an unwanted way.
  • Must attempt to control for these variables before conducting research.
  • Confounding variables: Variables other than the IV that have not been controlled.
  • Effects of the confounding variable are mixed up with the effects of the IV.
  • They have an unwanted effect on the DV and make it impossible to determine if the IV or confounding variable has produced the changes in the DV.
  • Confounding variables are systematic and occur throughout an experiment.
  • They are often related to the design of the experiment.
Comparison of Extraneous vs. Confounding Variables

Similarities:

  • Both are unwanted in any experiment.
  • Both make it difficult to determine which variable has caused a change in the DV.

Differences:

  • A CV has produced a change in the DV and has mixed up the results.
  • An EV may or may not affect the DV.

Population and Sample

  • Population: The entire group of research interest from which a sample is drawn.
    • Eg: All VCE students
  • Sample: A subsection of research participants selected from a larger group (population).
    • Eg: A selection of VCE students
Sample Details
  • A sample is more specific and can include more information than a research population regarding the number of participants, age ranges, and gender ratio.
  • Generally, include more information for a sample and one or two details for a population. This can be remembered with SNAG
    • Sample
    • Number
    • Age
    • Gender
  • E.g., A study looking at a research population of VCE students may have a sample of 120 students between the ages of 16 – 18 year olds, with 62 males and 58 females.
Participant Selection
  • A sample is taken that is REPRESENTATIVE.
    • Must closely represent its population.
  • Relevant participant characteristics of the population that may influence the study must be reflected (e.g., gender, socio-economic status, ethnicity).
Random Sampling
  • Ensures every member of the population has an equal chance of being selected.
  • Increases the chance of the sample being representative of the population.
Strengths
  • A large enough random sample is likely to be representative of the population, improving external validity.
Limitations
  • Small random samples may not be representative of the population, reducing the external validity.
  • It may be difficult, time-consuming, impossible, or unethical to obtain names of all members of the population.
Stratified Sampling
  • The population of interest is divided into strata (groups), and then a sample from each strata is chosen in the same proportions as they exist in the population.
    • Eg. age, income, ethnic background, religion, gender
Strengths
  • A large enough stratified sample is likely to be representative of the population, improving external validity.
  • Important subgroups of a population are ensured fair representation.
Limitations
  • It may be difficult, impossible, or unethical to obtain names of all members of the population.
  • It is more time-consuming than using a random sampling technique because of the need to form subgroups before sampling.
Convenience Sampling
  • Involves selecting participants who are readily available without making any attempt to make the sample representative of the population
  • EG. Students in a university class, volunteers who respond to an advertisement, people who are approached on the street
Strengths
  • Quick and easy to administer
  • Can use volunteers who may be more willing to participate in research
Limitations
  • It may be difficult, impossible or unethical to obtain names of all members of the population
  • It is more time consuming than using a random sampling technique because of the need to form subgroups before sampling

Experimental and Control Groups

  • Experimental Group: (IV is present)
  • Control Group: (IV is absent).
  • The participants in this group are exposed to the IV
  • The participants are NOT exposed to the IV, and provide a baseline measure so that the two groups can be compared
Random Allocation
  • Participants are just as likely to be allocated to the experimental group as the control group.
  • If the sample is representative of the population and extraneous variables are controlled for then the results can be generalised or applied to the group of interest / population.

Research Designs

  • Experimenters want to minimise the extraneous variables that might affect their results.
  • After they have chosen a sampling method and collected their sample, they need to employ a research design
  • Research designs determine how participants are allocated into the experimental group/s, control group or both
Three Types of Research Designs
  • Within-subjects design (repeated measures design)
  • Between-subjects design (independent groups design)
  • Mixed design
Within Subjects Design
  • Each participant is in the Control and Experimental Groups. These are THE SAME people
Advantages
  • This minimizes differences between participants.
  • Fewer participants are required.
Disadvantages
  • The order effect – participants become more familiar with the research and this might change their results.
  • Demand characteristics – participants could guess the purpose of study and change their results.
Between Subjects Design
  • Different participants are randomly allocated to either the control or experimental groups.
Advantage
  • No order effect (as only one condition is experienced).
Disadvantage
  • No control over participant characteristics (differences).
Mixed Designs
  • Mixed designs include a combination of within-subjects and between-subjects designs
  • Often, there are multiple periods of collecting results
Advantage
  • Can allow researchers to gather baseline measurements of participants before testing the IV to control for participant characteristics
Disadvantage
  • There can be higher attrition (participants dropping-out) due to longer duration of study
  • Can provide more precise and detailed results

Minimising Extraneous Variables

Types of Extraneous Variables
  • Participant Variables
    • Individual differences in participants
  • Experimenter Variables
    • Personal characteristics of the experimenter
  • Situational Variables
    • Differences in how the experiment is conducted
Examples
  • Participant variables (e.g. Age, gender, intelligence, motivation, mood, culture, race, health, expectations, etc.)
  • Experimenter variables (e.g. Personal contact with the participants, mood, cultural background, etc.)
  • Situational variables (eg. Non-standardised approach to research, the order effect, the placebo effect, artificiality)
Single-Blind Procedures
  • Single-blind procedures are used to minimise participant expectations.
  • Participants don’t know if they are in the experimental or control group.
Double-Blind and Triple-Blind Procedures
  • Both double-blind and triple-blind procedures are mainly used to control experimenter effects and participant expectations.
  • A double-blind procedure involves both participants AND experimenter/s (who interacts with the participants) being unaware of which groups participants have been allocated to.
  • A triple-blind procedure involves participants, experimenter and research assistants (doing data analysis) are unaware of the experimental conditions
Placebo Effect
  • Overcome by giving the control group a placebo.
  • A placebo is a fake ‘drug’ or treatment that is used so that participants do not know whether they are being exposed to the experimental condition.
Order Effect

  • In repeated measures experiments, participants are exposed to more than one treatment condition.

  • To overcome the order effect, counterbalancing is employed.

  • Counterbalancing involves systematically changing the order of the treatments or tasks for participants in a balanced way
    \n### Non-Standardised Instructions and Procedures

  • Standardised instructions and procedures are used to minimise any extraneous variables so that the results can be collected in a uniform and fair way

Summary of Types of Extraneous Variables
  • Participant characteristics – personal differences of participants that might impact IV such as mood, time of day, personal needs, health conditions, expectations, etc.
  • Experimenter effects – experimenter expectancy or beliefs that might influence change of behaviour towards participants, biases towards participants
  • Order effects – multiple conditions might impact the performance through practice, boredom or carry-on of other conditions, (counteracted through counterbalancing)
  • Non-standardised approach to research– differences in the conduct of an experiment (instructions or procedures) that might alter the results
  • Placebo effect - a change in a participant’s behaviour due to their belief that they are receiving a kind of experimental treatment, rather than the effect of the IV

Ethical Concepts and Guidelines

Ethical Guidelines

Role of the researcher (beneficence & non-maleficence)

  • Informed consent
  • Voluntary participation
  • Withdrawal Rights
  • Confidentiality
  • Debriefing
Role of the Researcher
  • The Researcher must primarily guard the welfare of participants, to ensure that they suffer no physiological or psychological harm. This is also known as the no harm principle
Informed Consent Procedures
  • Prior to commencing the study, participants must be made aware IN WRITING of:
    • The nature and purpose of research
    • Method
    • Withdrawal rights and confidentiality
    • Any risks/inconveniences/discomforts they may encounter
  • Legal guardians must provide consent for child participants or people who are unable to give consent (under 18s).
Voluntary Participation
  • The participant must choose to participate.
  • Must be of “free will”, meaning there should be no pressure to participate or negative consequences if they choose not to participate.
Withdrawal Rights
  • The participant has the right to leave the study at any time.
  • They do not have to provide a reason for their withdrawal.
  • There must be no negative consequences surrounding the choice to withdraw.
  • They also have the right to remove their results from the study at any time
Confidentiality
  • Participants must not be identified or identifiable without consent
Debriefing
  • Debriefing is where participants are informed of the study’s true purpose, after the experiment has taken place.
  • Should refer participants to relevant assistance if there are any issues post experiment.
  • Debriefing is crucial when deception has been used.
Use of Deception
  • Providing specific information about the study may influence how participants think, feel, and behave, and therefore influence the results
  • Therefore, secrecy or deception may be employed as long as:
    • No harm is done to the participant
    • The participant is debriefed after the experiment
Ethical Concepts
  • Integrity: ensures that there is some inherent value or benefit in studying something appropriately regardless of whether the findings are desirable or undesirable
  • Beneficence: researcher’s responsibility to maximise the potential benefits of the research and minimise the risks of harm or discomfort to all research participants
  • Justice: fair distribution of benefits and burdens for participants and the research population
  • Respect for human beings: includes participant rights (such as the APS ethics)
  • Non-maleficence: avoiding the causations of harm

Other Types of Research

  • Controlled experiment
  • Cross-sectional studies – No longer in the SD
  • Case studies
  • Fieldwork (including focus groups, observational studies and yarning circles)
  • Self-reports (including questionnaires, rating scales, interviews)
  • Literature reviews
  • Modelling and Simulation
  • Product, process or system development
Controlled Experiment
  • A controlled experiment involves an experimental investigation of the relationship between one or more IVs and a DV
Limitations
  • Controlled experiments require strictly controlled conditions, which may be difficult to maintain, so results may be influenced by extraneous variables.
  • Participant behaviour may be influenced by the artificial nature of the setting.
  • It may be unethical or impossible to conduct a controlled experiment on a particular variable.
  • External validity may be low if the conditions are too artificial to extrapolate results to the population of interest outside the experiment.
Case Studies
  • A case study is an in-depth investigation of some behavior or event of interest in an individual, group, organization, or situation.
Strengths
  • Avoids artificiality, therefore more realistic participant behavior.
  • Allows for little researcher intervention.
  • Ability to produce rich qualitative data.
Limitations
  • Very small sample size – (therefore results cannot be conclusive or generalized to a larger research population).
  • Potentially susceptible to researcher bias.
  • Repeatability is usually not possible.
  • Difficulty in controlling variables.
Fieldwork
  • Fieldwork involves observing and interacting with a selected environment (usually more relaxed), usually to determine correlation, rather than a causal relationship.
Fieldwork is conducted through a range of methods, including:
  • Qualitative interviews,
  • Observational studies
  • Questionnaires,
  • Focus groups
  • Yarning circles.
Strengths
  • Allows for little researcher intervention.
  • Setting avoids artificiality as occurs in a more natural setting.
  • Often the only type of research available (eg. studies observing people with a rare disease).
Limitations
  • Cannot determine the cause of behavior (as variables cannot be controlled).
  • Potentially susceptible to researcher bias (as it is subjective).
  • May involve demand characteristics or social desirability and therefore lead to artificial responses.
Self-Reports
  • Involves a participant providing answers to questions prepared by a researcher.
  • They include questions that require the participant to share a personal account which may include their beliefs, attitudes or feelings on any number of topic
They may include:
  • Questionnaires
  • Rating scales
  • Interviews
Strengths
  • Can collect a large amount of data in a short amount of time.
  • Anonymity on some self-reports is effective in gaining honest responses.
  • Easy to compare responses
Limitations
  • Not objective data, therefore prone to bias.
  • Participants may give false or misleading information.
  • Responses are subject to change based on mood, interpretation, or other participant characteristics.
Literature Review
  • Literature reviews involve collecting and analysing secondary data in order to give comprehensive analysis of a topic
Strengths
  • Useful for gathering initial information using existing secondary data
  • May be useful at determining changing trends over a period of time
Limitations
  • May lack depth
  • Studies may be selected using bias and therefore miss important details
Modelling and Simulation
  • Once a model has been made, a simulation uses the model to replicate and study the behavior of a real or theoretical system
Strengths
  • Both are a safe way of testing new devices, therapies or treatments that may be otherwise dangerous or unethical
  • Can test a product before it’s created and refine it
Limitations
  • May not entirely reflect actual real-world situations due to artificiality
  • May be expensive and require lots of data and resources
Product, Process or System Development
  • Identifying a health or social well-being need and development something that might assist

Analysing and Interpreting Data.

Collecting Results
  • Qualitative data is concerned with the ‘qualities’ or characteristics of what is being studied. It includes any type of data that is not numerical.
  • Quantitative data is information on the ‘quantity’ of what is being studied. It encompasses anything numerical
Primary Data
  • Primary data is information collected directly from the source by the researcher (or through others) for their own specific purpose;
Limitations
  • It can be time-consuming to collect and process.
Secondary data
  • Secondary data is information collected by someone other than the original user who did so for their own purpose
Advantages
  • Secondary data tends to be readily available and takes less time, especially after knowing where and how to look.
Analysing and Interpreting Data
  • After research has been conducted and results collected:
    • Results are summarized, organized, and described (Descriptive Statistics)
    • Results are interpreted so they can be understood (Inferential Statistics)
    • Interpretations are made about the data
Descriptive Statistics
  • Used for organizing, summarizing, and describing results
  • Descriptive Statistics include:
    *Graphing Data
    *Correlations
    *Distributions
    *Measures of Central Tendency
    *Measures of Variability
Measures of Central Tendency
  • Mean: Average
  • Median: Middle score when numbers are lined up
  • Mode: Most common number

Reliability and Validity

Internal Validity
  • Refers to whether a study investigates what it sets out or claims to investigate.
Reliability
  • Research must also aim to be reliable that is the extent to which results from a study are consistent, dependable and stable under the research conditions to ensure repeatability and reproducibility
Repeatability
  • Repeatability refers to the degree to which a specific research investigation obtains similar results when it is conducted again under the same conditions on all occasions.
Reproducibility
  • Reproducibility refers to how close the results are to each other when an investigation is replicated under Changed conditions.
Accuracy
  • Refers to how closely the measurement tool relates to what is being measured (e.g., high or low accuracy)
Precision

Refers to how closely a set of measurement values agree with each other (which helps in establishing a relationship e.g., the IV influences the DV in one clear direction)

Distinguishing between Scientific and Non-Scientific Ideas
  • Scientific ideas (Based on Fact)
  • Non-scientific ideas (Opinion & Anecdote)
    Conclusions in research should only be inferred from the evidence presented, rather than by non-scientific ideas

External Validity and Generalisations

  • If there is a high level of internal validity, then external validity can be considered.
  • External validity refers to whether the results of the research can be applied to similar individuals in a different setting.
  • If external validity is high, then a generalisation can be made for the broader research population