Types of experiments

• A controlled enviornment where CV's and EV's are attempted to be minimalised.
• The IV is manipulated to show the effect on the DV and then the Dv is then measured.

Advantages

• Keeps good level of control when regarding the CV's and EV's, this shows that there will be little interference between CV/EV and DV, this shows that more of a cause and effect releationship can be established between IV and DV, therefore increasing the internal validity.
• Can also be easily replicated, because of the standarised procedure researchers world wide are able to preform the experiment, if the same results are obtained then external validity is acredditied however, if results are not repeated then it shows the original is wrong stopping false data from being transmitted.

Disadvantages

• Lab experiments do not represent real life well meaning the may lack ecological validity.
• Furthermore in lab experiments it may be easier to discover the orignal aim opening the experiment up to higher readings in demand characteristics therefore questioning the internal validity of the experiment.

• A natural setting where the researcher goes to the participants, the DV is still measured and the IV is still manipulated.

Advantages

• More of an enviornmental setting, this means that the behaviour observed or created is more relateable to everyday life.
• Participants are unaware that they are being studied on this means that behaviour is likely to be more natural which reduces the spread of demand characteristics.

Disadvantages

• May lack internal validity, this is because the CV's and EV's are harder if not impossible to control, this leads to questionable data; was the behaviour due to the CV or IV.
• Participants are unaware they are being studied on, this is violation of privacy and the participants have possibly not given informed consent therefore disregarding the ethical issues set by the BPS

• These type of experiments involve no manipulation of IV and letting natural processes occur. DV maybe natually occuring e.g. exam results or could just be measured by researcher.

Advantages

• More ethically obtainable as manipulating IV can sometimes be unethical
• Externally higher than other experiments, natural experiments represent real-life scenarios for example measuring the effects an earthquake has on stress levels in humans.

Disadvantages

• The natural experiment may only occur rarely, furthermore they may be 'one-offs' meaning that they may be internally invalid.