Research Methods

IV

variable that changes

the variable for which quantities are manipulated (controlled, selected, or changed) by the researcher, and the variable that is assumed to have a direct effect on the dependent variable

DV

variable that is measured

the variable the researcher measures in an experiment for changes it may experience due to the effect of the independent variable

Aim

is a statement outlining the purpose of an investigation.

to write an aim

To investigate whether......

Hypothesis

testable prediction about the outcome of an investigation

How do you write a broad hypothesis

Basic hypothesis, mention IV and DV

How do you write a specific hypothesis

Also known as operationalized hypothesis

must include

- IV

- DV

- how variables were implemented/measured

- prediction abt direction results will take

- reference sample

Sampling Definition and types

process of selecting participants from a population of interest to participate in a research investigation.

Stratified

Convenience

Random

Sample

a subset of a population

Population

the larger group of research interest from which a sample has been drawn

What are the Ethical Guidelines

· Confidentiality

· Debriefing

· Informed Consent Procedures

· Use of Deception in Research

· Voluntary Participation

· Withdrawal Rights

What does confidentiality mean?

Ensuring participants' personal information and data are kept private and secure.

What does debriefing mean?

Informing participants about the true purpose of the study and addressing any misconceptions after participation.

What does informed consent procedures mean?

Providing participants with all relevant information about the study to ensure they can make an informed decision to participate.

informed consent should be written

What does use of deception in research mean

When researchers intentionally mislead participants, but only when necessary and justified.

What does voluntary participation mean?

Ensuring participants freely choose to join the study

What does withdrawal rights mean?

Allowing participants to leave the study at any time without any negative consequences.

What are the ethical concepts

Beneficence

Integrity

Non-Maleficence

Respect

Justice

What is Beneficence

is the commitment to maximising benefits and minimising the risks and harms

What is Integrity

Integrity is the commitment to searching for knowledge and understanding and the honest reporting of all sources of information and results.

What is non-maleficence

Avoiding harm or potential harm is outweighed by the benefits.

What is Respect

The ethical concept of respect involves considering the value of living things, giving due regard, and considering the capacity of living things to make their own decisions.

What is justice?

Justice involves the moral obligation to ensure that competing claims are considered fairly, that there is no unfair burden on a particular group from an action, and that there is fair distribution and access to the benefits of an action.

What is stratified sampling

Participants are recruited to match the proportions of social groups in the population.

What is random sampling

Random participants are selected from the population.

What is convenience sampling

Participants are selected based on ease of access.

What is an EV?

An extraneous variable (EV) is any variable other than the IV that may affect the DV.

What is between subjects design

Participants are allocated to different groups where each are exposed to a different condition.

What is within subjects design

Each participant is exposed to both the experimental condition and the control condition.

What is mixed design

A mix of both types of design is used, with both between subjects and within-subjects comparisons.

Define Random Allocation

uses chance to determine how participants are assigned to groups.

Strengths and Weaknesses of a mixed subjects design

Benefit

Differences in participant variables between groups are controlled in the within subjects design element.

Can test the effect of multiple independent variables on a dependent variable in one investigation.

Testing multiple independent variables in one investigation can be time and cost effective compared to completing two or more separate investigations.

Limitation

There is a higher rate of participant withdrawal from the study than using a between subjects design alone, which can be detrimental to the internal validity.

There is less control over participant knowledge of the study. Prior participation in the first condition may influence their behaviour while completing the second condition, than when using a between subjects design alone.

There is less control over differences in participant variables between groups in the between subjects element, which may influence results in an unwanted way, lowering validity.

Strengths and Weaknesses of a within subjects design

Benefit

In a within subjects design, there is no extraneous variable of participant variables between groups, improving validity.

Fewer participants are needed than in a between subjects design.

Limitation

There is less control over participant knowledge of the study. The extraneous variable of prior participation in the first condition may influence their behaviour while completing the second condition.

It is more time consuming than a between subjects design because both conditions cannot be tested at the same time.

There is a higher rate of participant withdrawal from the study than in a between subjects design because the DV has to be measured multiple times.

Strengths and Weaknesses of a between subjects design

Benefit

A between subjects design is the most time-efficient design because both groups can be tested at the same time and no pre-testing is required.

It has a lower rate of participant withdrawal than a within subjects design because participants only complete one condition.

There is better control of participant knowledge of the study and there is no effect of prior participation extraneous variables influencing results compared with a within subjects design.

Limitation

More participants are needed in a between subjects design than a within subjects design.

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There is less control over the extraneous variable of participant variables between groups, which may influence results in an unwanted way, lowering validity.

What is a controlled variable

variables that the researcher holds constant in an investigation.

External Validity

Whether the results of the research can be applied to similar individuals in a different setting.

What does lack of external and internal validity result in

●A lack of internal validity means no conclusions can be drawn.

●A lack of external validity means that the results may not apply to individuals or situations outside the study population - they cannot be generalised.

Generalisability

the extent to which research findings can be applied to the population of interest, picking the right sampling technique is important.

How can generalisability be improved

Large and Diverse Sample Size/Population

Control EV

Random Sampling/Allocation

Primary vs Secondary Data

•Primary data is any data we have collected ourselves.

•Secondary data is any data that has been collected by someone else.

Objective vs Subjective Data

Objective Data is information that is measurable, observable, and verifiable by others

Subjective Data is information that is based on personal opinions, interpretations, emotions, or self-reports.

What is a case study

An in-depth investigation of a single person, group or situation, often used when only a very small number of participants is available or when it would be unethical to create the situation experimentally.

What is classification and Identification

A methodology that involves sorting and categorising phenomena based on shared characteristics, often to label or identify specific types or groups.

what is a Correlational Study

A study that measures two or more variables to see how strongly they are statistically related, without manipulating them or inferring cause and effect.

what is fieldwork

An investigation conducted in real-world, natural settings (such as homes, schools or communities) using methods like:

Observations

Interviews

Questionnaires

Focus groups

Yarning circles

what is literature review

A detailed synthesis of existing published research and viewpoints on a particular topic, which summarises, critiques and connects prior findings instead of collecting new primary data

what is modelling

Building a physical or conceptual representation of a system so that it can be examined, tested or explained.

what is simulation

Using a model to recreate and study the behaviour of a real or theoretical system under controlled, often safe and repeatable, conditions.

what is product, process and system development

Research focused on designing or improving products, procedures or systems in order to better meet human needs or solve practical problems.

Advanatages of classification and Identification

Provides a common language for scientists to communicate (e.g., everyone knows what "Type 1 Diabetes" means).

Helps simplify complex information into manageable groups.

Advanatages of Correlational Study

Can be used to make predictions about one variable based on another.

Allows researchers to study variables that are unethical to manipulate (e.g., smoking and lung cancer).

Advanatages of fieldwork

High ecological validity, meaning the results are more likely to reflect how people act in the "real world."

Can capture complex social interactions that don't happen in a lab.

Advanatages of literature review

Saves time and resources by utilizing existing data rather than starting from scratch.

Helps identify gaps in current research that need more investigation.

Advanatages of modelling

Helps visualize and explain concepts that are too small (atoms) or too large (the solar system) to see.

Allows for testing without risking real-world objects.

Advanatages of simulation

Allows for safe and repeatable testing of dangerous scenarios (e.g., flight simulators).

Can "speed up" time to see long-term effects (e.g., climate change simulations).

Advanatages of case study

Provides highly detailed, in-depth data on a specific phenomenon.

Allows for the study of rare or unique conditions that would be unethical to reproduce in a lab (e.g., a specific brain injury).

Advanatages of product, process and system development

Leads to practical solutions and innovations that solve real-world problems.

Improves efficiency and safety in existing systems.

Disadvantages of product, process and system development

Often requires a large amount of funding and specialized expertise.

May focus too much on the "how" (practicality) and ignore the "why" (theoretical understanding).

Disadvantages of case study

Results cannot be generalized to the wider population because the sample size is only one or a few people.

Higher risk of researcher bias, as the researcher may become too involved with the subject.

Disadvantages of simulation

Can be extremely expensive to develop the software/hardware.

Participants may not act realistically because they know it's "not real."

Disadvantages of modelling

It is a simplification of reality and may leave out critical details.

The model is only as good as the data used to build it.

Disadvantages of literature review

The researcher might be biased in which studies they choose to include (selection bias).

If the original studies were flawed, the review will also be flawed.

Disadvantages of fieldwork

Lack of control over extraneous variables, making it hard to replicate exactly.

Can be extremely time-consuming and expensive to conduct.

Disadvantages of Correlational Study

Cannot establish causation (you don't know if A caused B, B caused A, or a third variable caused both).

Extraneous variables are not controlled.

What is a controlled experiment

An investigation where the researcher manipulates an Independent Variable (IV) to see the effect on a Dependent Variable (DV), while keeping all other variables constant.

Advantages of a controlled experiment

Establishes Cause-and-Effect: It is the only method that allows you to say "X caused Y."

High Control: Researchers can control extraneous variables (like noise, temperature, or age) to ensure they don't mess up the results.

Replication: Because the procedure is strictly controlled, other scientists can repeat the experiment to see if they get the same results.

Disadvantages of a controlled experiment

Artificiality: Because it often happens in a lab, participants might act differently than they would in the real world (low ecological validity).

Ethical Limitations: You cannot manipulate some variables (e.g., you can't force people to smoke to see if it causes cancer).

Disadvantages of classification and Identification

Can lead to oversimplification, where unique differences between individuals are ignored.

Labeling can carry social stigma (especially in mental health).

random errors

Unpredictable variations in the measurement process that result in a spread of readings. They affect the precision of an investigation but can be reduced by repeating measurements and calculating an average.

Personal Errors

Human blunders, mistakes, or miscalculations (e.g., misreading a scale or failing to follow instructions). These are not considered "scientific" errors and should be avoided or excluded from analysis

Systematic Errors

Errors that cause readings to differ from the true value by a consistent amount each time (e.g., an uncalibrated scale). They affect the accuracy of the results and cannot be reduced by averaging.

Accuracy vs. Precision

Accuracy: Accuracy relates to how close a measurement is to the true value of the quantity being measured

Precision: refers to how close a set of measurement values are to each other

True Value

The true value is the value, or range of values, that would be found if the quantity could be measured perfectly.

Uncertainty

A quantification of the doubt that exists about the result of any measurement (the range within which the true value is expected to lie).

Repeatability

how close successive measurements of the same quantity are when carried out under the same conditions.

Reproducibility

how close measurements of the same quantity are when carried out under different conditions.

Validity

The extent to which an investigation actually measures what it claims to be measuring.

Internal Validity

Did the IV actually cause the change in the DV?

External Validty

Can the results be generalized to the wider population?

How to increase Internal validty

Random Allocation

Randomly assigning participants to the experimental or control groups. This reduces participant variables

Controlling Extraneous Variables

Identifying "nuisance" variables (like age or diet) and making sure they are the same for everyone.

How to increase external validity

Representative Sampling:

Instead of just using your friends (convenience sampling), use Random Sampling or Stratified Sampling. This ensures your group looks like the "real world."

Increase Sample Size

A larger group is usually more representative than a small group.

How can researchers improve repeatability

1. conduct multiple trials under same conidtions and participants -> calculate average

How can researchers improve reproducibility

1. testing with different participants/researchers and seeing if results come out the same

How can researchers improve true value

1. control EV

2. make sure instruments/equipment are tested and correctly set before use