Investigation designs

Investigation designs

Experimental, observational, qualitative

Experimental investigation

The investigator examines behavior by manipulating the independent variable

Control group

The group which is not exposed to the independent variable, and creates baseline data to compare the impact of the IV on the experimental group

Experimental group

Participants who are exposed to the IV. The data will indicate what effect the IV had on the DV

Random selection

The process of randomly assigning participants to different groups in an experiment, ensuring that each participant has an equal chance of being placed in any group. This helps to eliminate bias and increases the validity of the results.

Random allocation

The process of assigning participants to experimental or control groups through random methods, ensuring that each group is statistically equivalent for comparison.

Advantages of experimental design

Experimental designs allow for control over variables, making it easier to establish cause-and-effect relationships. They also reduce confounding variables and ensure more reliable results. Also results in more accurate data

Disadvantages of experimental design

lack external validity due to the controlled environment

Behaviour may not reflect real life behaviour

Blind study

A research method where participants do not know whether they are in the experimental or control group to prevent bias.

Double blind study

A research method where neither the participants nor the researchers know who is receiving the treatment or the placebo, helping to eliminate bias in the results.

Qualitative design

A research approach that collects non-numeric data to understand concepts, opinions, or experiences, focusing on subjective interpretations.

Mainly conducted in the form of discussions where people are asked open ended questions to prompt in-depth answers

Advantages of qualitative design

Include rich, detailed data and insights into participant experiences, flexibility in data collection, and the ability to explore complex phenomena.

Allow to uncover the reasons behind feelings

Disadvantage of qualitative design

Includes potential researcher bias, difficult to generalize findings, and time-consuming data analysis.

Results cannot be verified

Observational design

When a pre-existing variable is used to separate participants and see their effect.

Commonly used when the participants cannot be randomly assigned due to it being unethical or impossible

Can be done in the form of:

• Correlational studies

• Cross sectional studies

• Sequential studies

• Naturalistic observation

Advantages of observational design

More ethical due to no manipulation

A wide variety of IV can be done due to no random allocations

Behavior reflects real life behavior

Disadvantages of observational design

No control over variables

Participants may act different if being watched ~Naturalistic observation

Experimenter bias ~ Naturalistic

No cause and effect ~ Cross sectional, correlational, sequential

Participant, situational, and extraneous variables can influence the data due to no control causing inaccurate data to be collected

different types of data

Quantitative

Qualitative

Subjective

Objective

Quantitative data

Data in the form of numbers

• Data is graphed on bar graph if it has pre-existing categories

• Data is graphed on line graph if the categories have naturally occuring order

Qualitative data

Data in the form of words and descriptions

• Organised into a frequency table

Objective data

Data which is observable, factual, and can be verified

Subjective data

Data which is self reported or only based on opinions

• Interviews

• Surveys

• Scale ranking

Quantitative data ~ Advantages & Disadvantages

Advantages:Easy and quick to analyze and is unbiased

Disadvantages:It doesn’t provide answers to the why and how factors

Qualitative data ~ Advantages & Disadvantages

Advantages

• Allows to gather peoples in depth opinions and any lived experiences

Disadvantages:

• Time consuming to analyze due to having to divide answers into themes

Objective data ~ Advantages & Disadvantages

Advantages

• Data is factual, unbiased, and can be verified

Disadvantages

• Hard to collect in the field of psychology

Subjective data ~ Advantages & Disadvantages

Advantages

• Allows research into areas where objective data cannot be collected

Disadvantages:

• No way of ensuring that the participants are being truthful

Reliability

The consistency of your procedures and results

• Was the procedure consistent?

Internal validity

The accuracy of the investigation design

Target population & sample

Target population: The whole group of people you are trying to observe

Sample: The subset of the population which is being studied

External validity

How well the results collected can be applied in real world scenarios

Confounding variables

Any extraneous variable which has influenced the results in any way which causes the validity of the results to decrease

Extraneous variables

Any variable that could not be controlled (other than the IV) that could potentially affect the results and lower the accuracy

Participant variables

Individual differences that participants bring to the study

Examples

• Gender

• Intelligence

• Personality

• Motivation

• Emotional state

Situational variables

Associated with the experiment itself and may influence the results in an unwanted way

Example

• Background noise

• Time of day

• Temperature

Placebo effect

Refers to whenever a participants response is influenced by their expectation to of what to do or how to think or feel, rather than actually being influenced by the IV

Ethical principles

A set of rules which describes how researchers to treat their participants

IVCARDD

Do Not harm

Participants must not be exposed to situations where physical or psychological harm is likely

The participants should be entering and exiting the study with the same or better mental health

*Well being must be monitored throughout the study*

Informed consent

The researcher must inform the participant of all aspects that are likely to influence their decision of participation

• Written consent

• If the participant is younger than 16 then a parent must consent

Voluntary consent

Participants must have the freedom to say they don’t want to participate

• The participant cannot be pressured or coerced in any way

Confidentiality & Anonymity

Information given by participants and individual results must be kept confidential

Results should be anonymous

Only relevant information to the study must be collected

Accurate reporting

Researchers must share the accurate results even if their hypothesis was not supported

Raw data cannot be used without the participants consent, only the mean data scores can be used for external purposes

Right to Withdraw

The participant should be allowed to withdraw from the study at anytime

If any obvious harm is being done to the participant then they should be removed immediately

Debriefing

At the end of the study the participants should be fully informed of all aspects of the study

In case the participants experience distress following the experiment, they should advised services available to them