experiments Flashcards
lab, field, natural, iv, dv
what is an experiment?
a research method which demonstrates casual relationships
what do all experimental methods involve?
iv and dv
what are the different types of experiments?
- lab
- field
- quasi
what is a lab experiment?
a research method in which the experimenter manipulates one or more independent variables and measures the effects on the dependent variable under controlled conditions
strengths of lab experiments
- They allow for precise control of extraneous and independent variables. This allows a cause-and-effect relationship to be established
- It is easier to replicate a laboratory experiment. This is because a standardized procedure is used and there is high control of extraneous variables
weaknesses of lab experiments
- Low ecological validity as the artificiality of the setting may produce unnatural behavior that does not reflect real life. This means it would not be possible to generalize the findings to a real-life setting.
- demand characteristics as pp aware they’re in a study or experimenter effects may bias the results and become confounding variables.
what is a field experiment?
- Experiment that takes place in a real-life, natural setting
- Experimenter manipulates one or more independent variables and measures the effects on the dependent variable
- Ppts are unaware they are being studied, and the experimenter has less control over the extraneous variables.
strengths of field experiments
- higher ecological validity as the environment is natural and more like real life, can generalise findings to target population
- demand characteristics are less likely to affect the results, as participants may not know they are being studied
weaknesses of field experiments
- low reliability - there is less control over extraneous variables that might bias the results. this makes it difficult for another researcher to replicate the study in exactly the same way.
- The researcher’s control over the environment is reduced in the real world. Therefore extraneous variables are more likely to distort the results and greatly reduce internal validity.
- they have ethical issues. for example, as the setting is natural and deception is used, they may be unaware that they are in a study. therefore, there is no informed consent and right to withdraw is compromised
what is a quasi experiment?
Research method in which the experimenter observes the effects of a naturally occurring event or situation on the dependent variable without manipulating any variables.
used when iv can’t be controlled due to ethical or practical reasons
strengths of quasi experiments
- Behaviour in a quasi experiment is more likely to reflect real life because of its natural setting and lack of involvement from the researcher, so findings can be generalised to other real life settings i.e. very high ecological validity.
- It can be used in situations in which it would be ethically unacceptable to manipulate the independent variable, e.g., researching stress.
weaknesses of quasi experiments
- low internal validity - have no control over the environment and other extraneous variables which means that the researcher cannot always accurately assess the effects of the I.V,
- There is no control over extraneous variables that might bias the results. This makes it difficult for another researcher to replicate the study in exactly the same way