Experimental & Non-Experimental Investigations

Laboratory, Field, Natural, Correlational, Observational, Quesionnaire, Interviews and case studies.

HideShow resource information

Experimental Investigations - Laboratory Experimen

  • Conducted in a highly controlled enviroment (often a laboratory).
  • The IV is directly manipulated by the researcher, the DV is measured and the researcher aims to control all CVs.


  • Testing for cause and effect (being able to prove that the change in the DV was caused by the manipulation of the IV).
  • Control over confounding variables as the enviroment is highly controlled.


  • Lack of ecological validity (unable to generalise the findings from such an artificial, controlled enviroment to the real world).
  • Demand characteristics whereby the participant behaves artifically in accordance with what they think the researcher is looking for.
1 of 8

Field Experiment

  • Conducted in a natural setting (workplace or school).
  • The IV is directly manipulated, the DV is measured and there is an attempt to control the CVs.


  • Improved ecological Validity (because of the natural setting).
  • Testing for cause and effect.


  • Less control over the CVs (compared to a laboratory experiment).
  • Time and cost consuming (because of the natural setting).
2 of 8

Natural Experiments (quasi-experiments)

  • Conducted in a natural setting (workpace or school).
  • Wait for a naturally occuring change in the IV and measuring the DV.
  • No Control over the CVs.


  • High ecological Validity (natural enviroment and lack of manipulation of any variables by the researcher).
  • Few demand characteristics.


  • Ethical Problems (difficult to obtain full consent).
  • Impossible to replicate due to waiting for the IV to occur naturally.
3 of 8

Non-Experimental Investigations - Correlational An

  • Measures the relationship between two co-variables.
  • Correlation coefficients range from +1 to -1.
  • +1 indicates a perfect possitive correlation (as on variable increases, so does the other).
  • -1 indicates a perfect negative correlation (as one increases, the other decreases).


  • Measures the strength and direction of relationships (use of correlation coefficient).
  • measure several variables at once.


  • Issue of casuality (cause and effect can't be established by any non-experimental investigation).
  • Misinterpretation of Data.
4 of 8

Observational Studies

  • The scrutiny of ongoing behaviour in its natural setting.
  • Participant observation - the researcher joins the group under investigation.
  • Non-Participant observation - the researcher remains external from the group.
  • Behaviour sampled through time sampling or event sampling.


  • High ecological validity.
  • Good exploratory/preliminary research tool.


  • Controlling variables
  • Ethical issues (can't tell participants because of demand characteristics).
5 of 8

Questionnaire surveys

  • Using a Pen and Paper method.
  • Questions can be opened or closed.
  • The questions must not be leading, ambiguous, double-barrelled or contain jargon.


  • Simplicity (easiest type of research conducted).
  • Ease of analysis (from closed data as the questions are quantitative).


  • Untruthful answers (because of demand characteristics).
  • Leading questions.
6 of 8


  • Can be structured, unstructured or semi-structured.
  • Structured produces quantitative data.
  • Unstructured and Semi-structured produces qualitative data.
  • Conducted face to face
  • Recorded through writting or tape.


  • Flexibility (especially semi-structured and unstructed where questions can be added at any time).
  • Ability to identify personal aspects of behaviour.


  • Demand Characteristics.
  • Difficulty in analysis of data which could lead to misinterpretation.
7 of 8

Case Studies

  • Detailed accounts of one individual or a few individuals.
  • Researcher will try to get as much information as possible from each individual.
  • These include personal history, background, test results, personality ratings etc.


  • Extremely detailed
  • Ability to indentify personal aspects of behaviour.


  • Demand Characteristics.
  • Difficulty in analysing data as the data will be vast.
  • Hard to generalise to other people because it is specific data.


8 of 8


No comments have yet been made

Similar Psychology resources:

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