Research Method

Research process

Validity and Reliability

Sampling methods

Aims and hypothesis

Types of experiment

Types of Observation

Sampling participants

1.Develop an aim and hypothesis

2.Selection of research method

3.Operationalization of variables/defining measurements

4.Ethical considerations

5.Recruit participants

6.Collect data

7.Analyse data

8.Evaluate the quality of the research

An aim identifies the purpose of the investigation. It is a straightforward expression of what the researcher is trying to find out from conducting an investigation.

A hypothesis is statement of prediction. Predicts the relationship between the variables in the experiment or correlation.

directional hypothesis

non-directional hypothesis

alternative hypothesis

null hypothesis

An experiment is a method used in science to test whether or not a theory (thought) is true. It involves changing one thing (IV), keeping everything else this same (control) and taking measurements (DV). This allows the person doing the experiment to see the effect this one variable has on the measurement.

variables

Independent variable (IV) = the variable that is being changed (this is the variable the experimenter thinks will effect the measurements).

Dependent Variable (DV) = the variable that is measured (the measurement change depends on changes to the IV)

Extraneous Variable = this is a variable that will effect the results if it is not controlled.

Control variable = a variable that has been controlled by the experiment so it does not effect the results.

different types of experiment

Lab Experiment = an experiment that happens in a controlled environment like a laboratory

Field Experiments = an experiment in a natural environment, but there is still an independent variable being changed by the researcher. There is likely to be some effort to control confounding variables.

Natural Experiments = an experiment which happens in a natural environment, but the researcher does not change variable, the variable changes naturally

Experimental design

1.Independent Measure Design:There is a different group of participants for each condition of the independent variable.Each participant only participates in one condition of the IV.

  1. Repeat Measure Design:
    Each participant participates in all condition of the IV.
  1. Matched-Pair Design
    Each participant only participates in one condition of the IV like an independent group design. However, participates are put into pairs with people with similar characteristics with each other.

volunteer

Naturalistic = investigation in a natural environment, where the researcher has no control over who participates or the situation.

Controlled = Part of an experiment as they happen in a environment that the researcher can control and the participates are pre-selected.

Covert = participant is unaware they are being observed.

Overt = participant is aware they are being observed.

Structured = the behaviors that will be observed are operationalized. A limited number of pre-determined and well defined behaviors will be observed. Could use time-sampling and event sampling.

Unstructured = observer notes what they see e.g. common, important and unusual things.

Participant observation = Researcher often joins the group they are studying or at least interacts with them. It s usually naturalistic and covert and involves the researcher recording the data as they interact with the participants.

Non-participant observation = researcher observes the participants from a distance e.g. watching through a one-way mirror or using a video camera.

*criticism: researcher bias

improved by Blind Studies/Inter-rater reliability

Event Sampling: tallying the number of times a operationalized (well defined) happens.

Time Sampling: the duration of the observation is first decided. It is then divided into intervals. The behavior performed by the participant is defined for each interval

*operationalization is a process of defining the measurement of a phenomenon that is not directly measurable, though its existence is indicated by other phenomena.

Standardization: keeping the experience of the investigation the same for every participant.

random

opportunity

ppt are invited to the study thru ads via email or notices. 2. Those replies becomes the sample. “Respond to the advert”

  1. Ppt are chosen because they are available. 2. Eg. University Students.
  1. all members of the population are allocated numbers and a fixed amount of them are selected in a unbiased way.

Self-report

1.Questionnaires:-usually a paper and pen test, however it could be online, no interaction between the participant and the researcher, more often than not questions are closed and assessed using rating scales with a standardized way of assessing the data

2.Interviews: a research method using verbal questions asked directly, typically face-to-face

2.Types of question
-closed question: a question were there only a limited number of answers

3.Rating scale: a rating is made along a scale

structured

unstructured

semi-structured

Validity

1.definition

a study is only valid if it measures what it is supposed to.-accurate

-In an experiment, this means that only the IV causes the change in the DV.

If a study has high external validity it means the results can be applied to other people and other cultures.

2.Things which decrease validity

Extraneous variables which effect the DV

Demand characteristics

Subjective and biased interpretation of qualitative data

Participant differences e.g. when using independent design

3.Types of validity

b. Ecological Validity: extent to which the results of the study can be applied to real life.

a. Internal Validity: the extent to which the study measures what it is supposed to.

c. Population Validity: extent to which the results of the study can be applied to other people.

d. Predictive Validity: extent to which the results of a test can predict performance/behavior.

e. Convergent Validity: extent of agreement between tests measuring the same variable.

Reliability

Things which affect reliability

Types of reliability

-External Reliability: extent to which the results of the study can be replicated.

-Internal Reliability: the extent to which the results of the study are consistent.

The participant’s mood and motivation

How objectively the participant’s data is interpreted

If a procedure is not very standardized it might be difficult for other researchers to do the same investigation with other participants.

If only a very narrow sample was used maybe the results will not be replicable with other samples of people.

Assessing reliability

Split-Half Method:
A questionnaire is split in to two halves

Test Re-Test Method:
Involves giving the participant the same test on two separate occasions

Inter-Rater Reliability involves two or more researchers rating an observation or the contents of an interview (qualitative data). The researchers then compare their ratings. The researchers may then see if their results correlate with each other. If the two or more researchers’ results are consistently similar then the results are considered to be reliable.

Correlation

Correlation means association - more precisely it is a measure of the extent to which two variables are related.

types of correlation

positive

negative

zero

Advantages and disadvantages of correlation

Adv.

can’t introduce some variables(lung cancer) in lab experiment

Disadv.

can’t see if one changes the other would change or not or how to change cuz correlation refers to the natural relationship between two naturally occurring variables

The third variable

Ethical issues

Problems in research that raise concerns 2. about the welfare of ppt (3. or may have a negative impact on society) [4. Aspects of the procedure 5. nature of study.]

Types of ethical considerations

Deception

Debriefing

Right to withdraw

Preceptive consent

Ethical guideline

Informed consent

Confidentiality

Privacy

Protection