Research Methods

Should cover the 9 methods, experimental designs, hypothesis, and extraneous variables, pilot studies, ethics, sampling techniques and reliability and validity. Will be expanded in future.


The 9 Methods- Questionnnaires

A self report technique which allows participants to directly report information, they consist of pre-written questions. They can be filled in online, face-to-face, on the phone or on paper. Useful for looking at opinions and attitudes. Open questions can produce detailed qualitative data, but closed tick box questions give quantitative data which is easily analysed.


  • Highly Replicable: simple to ensure participants follow the same procedure, good reliability.
  • Efficient: a large sample can be found quickly, a large amount of data collected.
  • Reduced Investigator Effects: Researchers not present, improved validity.


  • Dishonesty/Social desirability: people may modify their answers, reduces valididty.
  • Literate Participant Bias: an unrepresentative sample, reduction in population valididty.
  • Researchers not present: Participants cannot ask for help and may miss parts out due to confusion/
1 of 21

The 9 Methods- Interviews

A self-report technique in which partipants provide direct information. The researcher may have a structured interview in whch they do not deviate from pre-written questions in their pre-assigned order, or can hold a unstructured interview where they have a general idea of the questions they will ask but which have flexibility to change the course of questioning.


  • Complex Issues: the researcher can guage whether a paritcipant is distressed by the questioning.
  • Immediate follow-up: a researcher can rectify misunderstandings or get information they did not expect.
  • Rich Data: there are few constraints on answers.


  • Social Desirability: gives it reduced validity.
  • Low Inter rater reliability: often due to interviewer effects of age, gender, ethnicity etc.
  • Time Consuming: to prepare for and conduct, and then to analyse a large amount of detailed data.
2 of 21

The 9 Methods- Case Studies

A case stidy is an in-depth studu of an individual, group of people, institution or event, often with a narrow focus and taking place over a long period of time. It often involves other methods too, and associated ppeoepel may take part in the case study of an individual.


  • Impractical/unethical topics: allows investigation where research cannot be done experimentally.
  • Unique cases: challeneg existing ideas and suggest new hypotheses.
  • Complex interactions: are best suited to this kind of method, allow wide use of techniques.


  • Cannot generalise: only a limited number of people are investigated, cannot generalise tot eh population or easily replicate the experiments.
  • Ethical issues: the nature of the participants may mean they are young or have severe disorders.
  • Bias: a researcher can become too involved with a case, leading to subjective recall and making the findings unreliable.
3 of 21

The 9 Methods- Observations

In this method behaviour is watched and recorded. In a controlled observation a researcher will manipulate the variables of the environment, but these experiments can also be naturalistic and focus on observations in a natural environment. An unstructured experiment will involve taking a continuous stream of data, whilst a structured requires behaviour to be operationalised so that it can then be tallied.


  • Ecological Valididty: if participants are unaware they are being observed their behaviour is completely natural.
  • Impractical/Unethical: topics can be studied with this method.
  • Preliminary Research: useful to from new hypothesis or get ideas for research.


  • Ecological Valididty: if participants are aware they are observed their behaviour becomes unnatural
  • Ethical Issues: participants who are unaware cannot have informed consent, right to withdraw or confidentiality.
  • Low Reliability: situations are often unique, observers may disagree on judgments.
4 of 21

The 9 Methods- Content Analysis

This technique is used to transform qualitative data into quantitative data. An example would be using it to turn an interview transcript into quantitative data. A researcher must decide the material he will sample, then create a coding system for the categories. They can then analyse their sample by counting frequencies, with which statistical analysis can be carried out.


  • Reliability: easily replicated by accessing archived materials, high reliability.
  • Ecological valididty: based on real communication gathered in natural settings.
  • Presentation: Makes qualitative data easy to uunderstand.


  • Validity: researchers may be inconsistent with coding units or be subjective.
  • Time: large samples must be examined and prepared.
  • Ethics: participants are often unaware their material is being used as part of research.
5 of 21

The 9 Methods- Correlational Analysis

A technique used to show the strength of a relationship between two variables. It often uses secondary data. The findings could be illustrated through a scattergram or through correlation coefficients (a number ranging from -1 to +1, which shows the exact strength and direction of a relationship).


  • Efficient: participants and facilities are not required and they often use pre-existing data.
  • Impractical/unethical: topics which cannot be looked at experimentally can be researched.
  • Precise: it can tell the exact strength and direction of a relationship.


  • Cause and effect: we can say that variables are related but we do not know in which direction.
  • Innacurate conclusions: people can infer something that is not there, leading to misuse of data.
  • Curvilinear relationships: any situation where the results are not a linear relationship cannot be detected.
6 of 21

The 9 Methods- Experimental Method (Laboratory)

These usually takes place in in a special facility within a psychology department. The independant variable is directly manipulated, and its effect on the dependant variable directly measured. Extraneous variables are controlled as much as possible.


  • Cause and effect: the effect of the IV on the DV is isolated, and so cause and effect can be inferred with confidence.
  • Reliability: they operate under strict controls and are well documented, therefore easy to repeat.
  • Equipment: a dedicated research facility will have specialist equipment, e.g fMRI scanners.


  • Ecological validity: they experiment takes place in a very artificial environment.
  • Demand characteristics: participants will look to the researcher and the situation for clues as to how to behave.
  • Ethics: cannot be used in sitaution where it would be unethical to manipulate an IV.
7 of 21

The 9 Methods- Experimental Method (Field)

Field experiments function in the same way as laboratory experiments, except the lab is swapped for a real-life setting such as  a school, town centre or hospital.


  • Ecological Validity: due to the real world setting the results can be generalised to real life.
  • Demand charcteristics: greatly reduced as participants may be unaware they are taking part.
  • Cause and effect: the effect of IV on DV is isolated.


  • Extraneous variables: as the researcher has less control more extraneous variable casue a lack of valididty.
  • Ethics: if participants are unaware they are being observed, manipulation of variables may distress them, it is impossible to debrief them.
  • Bias: the researcher cannot control the participant sample, which may be biased in age gender etc, population valdidty is decreased.
8 of 21

The 9 Methods- Experimental Method (Natural)

In a natural experiment the researcher does not manipulate the IV at all, it is naturally occuring. They act only to measure the effect of the IV on the DV (it is therefore only quasi-experimental). An example might be the effects of child abuse on adult relationships.


  • Impractical/Unethical: other experimental methods cannot be used for this type of research.
  • Ecological validity: this is extremely high as the researcher is studying completely real situations.
  • Demand Characteristics: participants who are unaware they are being observed act naturally.


  • Extraneous variables: cannot be eleiminated due to the researcher having no control over environment, this affects the valididty of results.
  • Ethics: if participants are unaware then they do not have informed consent or the right to withdraw.
  • Reliability: as the natural events are often rare the studies are hard to replicate.
9 of 21

Experimental Deisgns:Independant Groups

Different participants are placed in each group, they are completely seperate.


  • Fair: only one set of stimuli needs to be prepared, both groups use the same stimulus.
  • Order effects: boredom, tiredness and learnign are reduced because particpants only experience one condition.


  • Expense: More particpants are required than in other designs.
  • Individual differences: results from different particpants are being compared, may affect conclusions.
10 of 21

Experimental Deisgns: Repeated Measures

The particpants are used in both condidtions, each person will participate twice.


  • Cost effective: far fewer participants required.
  • Individual differences: results form the same participants are compared, they do not affect the results.


  • Order effects: boredness, tiredness and learning affect results and conclusion valididty.
  • Extraneous variables: two sets of stimulus material need to be created: one could be more difficult.

Counterbalancing can be used to overcome this; half of the participants will do the control conditon then the experimental and vice versa.. Order effects are not eliminated but  they are now equal across both conditions so the negative effect is reduced.

11 of 21

Experimental Deisgns: Matched Pairs

Different participants are used in each condition, but are matched on key variables to form pairs.


  • Fair: only one set of stimuli is used.
  • Order effects: a participant will only experience one condition.


  • Difficulty: matching participants is difficult and time consuming, and may be innacurattte or incomplete. Participant variables are never fully eliminated.
  • Efficient: if one person leaves the experiment you lose two sets of data.
12 of 21

Aims and hypotheses

An aim is the purpose of a study. A written aim will make the research more focused and clarify what the researcher aims to discover.

A hypothesis is a precise, testable statement about the expected outcome of a piece of research. They come in three forms:

DIRECTIONAL HYPOTHESIS: a prediction of a specific outcome, will give a direction of a relationship.

NON-DIRECTIONAL HYPOTHESIS: when a researcher is less sure what is going to happen in a study they will sa that there will be a change, but not predict the direction it will go in.

NULL HYPOTHESIS:  when a researcher is confident that there will be no change when the independant variable is changed.

13 of 21

Extraneous Variables

An extraneous variable is anything other than the IV which might influence the DV. If not controlled and then affects the finding it is known as a confounding variable.

Participant variables are brought into the research by the participant, and result in differences in peformance, e.g age, gender, mood. Choose an appropriate experiemntal design to reduce this.

Situational variables are features of the research environment which create different experiences for participants, e.g temperature, time of day, noise. Use standardisation of conditions and instructions will reduce this.

Demand characteristics are clues in the research environment as to what the research hypothesis is, this can make them alter behaviour so as to appear normal. To reduce this a single blind technique is used, where the participant have no way of knowing which condition they are in.

Investigator effects are characteristics of the researcher that might affect participant repsonses, or the researcher might subconsciously try to influence results. A double blind technique reduces the effect.

14 of 21

Extraneous Variables cont.

Participant reactivity is the idea that participant performance may not be being affected by the IV but instead by the attention recieved during the study. It is known as the Hawthorne effect. Another example is social desirability, where the participants chnage their behaviour so as to appear more sociallly desirable.

15 of 21

Pilot Studies

Pilot studies are carried out so that researchers can forsee any problems that might arise during research.

They could be used to identify issues with method/design, instructions, procedures, material or measurements.

If problems are identified, the researchers can choose whether to rectify the problems or to abandon the experiment entirely. This prevents sample groups and stimulus materials being wasted.

Pilot studies are not possibe with natural experiments and case studies, as the situations are rare and so it would be wasteful to conduct a pilot study.

16 of 21

BPS Code of Ethics

The British Psychological Society attempt to solve the ethical issues that arise when scientific goals and the rights of paritcipants are in conflict. To do this they set 5 guidelines for psychologists.

PROTECTION FROM HARM: Psychologists have a duty to protect participants form physical and emotional harm. They should keep the risk they face at a level of ordinary life. They should ask colleagues to check their procedures, ask participants about health conditions they may have and stop the experiment if it looks as though it may harm the participant. They should also be given a debriefing and aftercare.

INFORMED CONSENT: A participant should always agree to be part of an experiment before it begins, and should be told as much about it as possible. They or their parents should sign a consent form. The carers of an adult will be asked if it is felt they are unable to make a decision by themselves.

DECEPTION: Researchers should not withhold any information from participants or actively mislead them about the true nature of the study, either to encourage them to give consent or to get more valid results. Exceptions include when the deception is minor, deemed scientifically justified by an ethics comitee and/or if participants are unlikely to object when the deception is revealed. Debriefing should be used afterward to explain the real aim and to reassure the participant and answer any questions.

17 of 21

BPS Code of Ethics cont.

CONFIDENTIALITY: Participants should feel confident that the study's report will not reveal anything that allows individuals to be identified. They should remain completely anonymous. To this end, psychologists should use letter, numbers or codes to keep track of data instead of participant names. They may also keep the location of the research a secret. Consent must be gained from participants if thier data will be used in a way that will not ensure confidentiality.

RIGHT TO WITHDRAW: Participants will be allowed to leave at any pint of the study, even after it has been completed, in which case they will have the data collected from them removed from the research. Participants should be informed of this at the beginning of the research and at suitable points during and after the research. Pressure should not be put on them to stay and they cannot be coerced with payment. Taks avoidance amongst children should be taken as a wish to withdraw.

Many institutions weigh up study based on the possible harm they will do vs. the benefit the study will bring. Psychologists who ignore these guidelines may be expelled from their institution, have thier research licenses revoked or face legal action from the participants.

18 of 21

Sampling Techniques


In this technique, the researcher fisrt obtains a list of everyone in the target population, then randomly selects the required number of pariticpants. Eveyone therfore has an equal chance of being picked.

Strength: The chances of a biased sample are slim, increasing population validity.

Weaknesses: It is difficult to gain the list needed, and it cannot be ensured eveyone is able or willing to take part. There is also a chance that sub-groups will be over or under-represented.


The researcher asks partipants who are easily accessed and willing to take part, for example psychology students.

Strength: It is time and cost efficient, sample sizes can therfore be large.

Weaknesses: Samples are likely to be skewed in terms of particpant back grounds. There are also ethical issues as the participants may feel obliged to take part..

19 of 21

Sampling Techniques cont.


The researcher will put an initial advertisement in a  public place or a newspaper, magazine, on the internet or through email asking for volunteers. They could also send out questionnaires which they aks to be returned.

Strength: This techniques is often a good way of reaching niche participants who are difficult to identify in the target population.

Weaknesses: Only the mist motivated and co-operative participants will volunteer to take part. This reduces population valididty and generalisability. Only people who see the advertisement can respond, possibly resulting in  a low sample size.

20 of 21

Reliability and Validity

Reliabilty is how consistent something is. If you said a study was reliable you would be able to repat the study and see the same results each time, unless the sample group is signififcantly differnt from the previous time.

Psychologists will repeat studies using the same measurements and procedures and see if there is positive correlation between the results.

If study is vaid if it measure what it claims to measure, i.e that the findings are true and legitimate.

INTERNAL VALIDTY: If the study has limited the effects of extraneous variables so that the outcome is as a result of the independant variable.

EXTERNAL VALIDITY: If the study has findign which can be generalised to things beyond the immediate research context.

  • ECOLOGICAL VALIDITY: the findings can be generalised to other settings;
  • POPULATION VALIDITY: the findings can be generalised to other people;
  • TEMPORAL VALIDTY; the findings can be generalised to other times.
21 of 21


No comments have yet been made

Similar Psychology resources:

See all Psychology resources »See all Research methods and techniques resources »