Within Psychology, experiments are research methods which are used to verify hypothesise made by psychologist and also bring clarity to subject matters within Psychology. True experiment is one of the main experimental methods which are believed to bring a high level of precision; it is also the only process that can assuredly establish causal relationships between variables. However, there is no experimental method that will provide perfect precision. A true experiment is carried out when the experimenter has total control over the fluctuating factors of the study. The main aspects of a true experiment are randomized assignments, independent variables and dependent variables. The importance of true experiments will be discussed further into depth.
Psychology has been as the scientific study of behaviour (Martin, Carlson & Buskist, 2010). It is vital in the research segment of psychology, that not only is experiments conducted but it is also evaluated, it should be weighed up as this then leads to conclusions and discoveries. The evaluation process includes examining the claim that the experimenter has put forth and assess all information of substance according to the claim made, then the results collected from the experiment then needs to be measured up against the claim to see if it supports it or whether it does not. In order to declare a statement as a fact within psychology, also in general, there needs to be appropriate research has been executed. It is crucial, that when conducting research and experiments, that the process is done as accurately and carefully as possible as the more accurate the research process, the more valid the results shall be (Howitt & Cramer, 2011). True experiment is often compare to quasi experiment, this method does not allow the experiments to control the assignments of participants to treatments, in other words, it selectively allocates subjects instead.
True experiment can often be branded as a laboratory experiment as it has many factors which share similar properties. For an experiment to be classified as a true experiment, according to Campbell and Stanley (1963) they must meet the three requirements listed:
• The alleged cause of a result is manipulated
• Participants are randomly allocated to conditions
• All other aspects are kept constant
If these requirements are not met, then the experiment is deemed as a quasi-experiment. As previously mentioned, it consists of three main characteristics which are experiment manipulation, randomized assignments, independent and dependent variables. The importance of experimental manipulation is that in order to find out whether two variables are causally associated then it is necessary for the experimenter to control one or more variables. However it would be unwise to manipulate many of the variables without keeping some of them the same, because if an experiment is totally different from all previously conducted experiments, it would be impossible to identify what cause such results. Randomized assignments is best defined as aimlessly allocating participants to different conditions and groups to avoid bias and prejudice from occurring, it also keeps the confounding variables constant (Howitt and Cramer, 2011). As explained by McBurney & White (2010), variables are factors of a condition that can change or carry different features with different condition. A dependent variable is the measurement of the participants; it has a causal relationship with the independent variable as if it affected by it. The variable which is manipulated by the experimenter is called an independent variable; this is assumed to have causal effect upon the dependent variable. The independent variable is totally independent amongst all other variables due to the assignments to the different experiment conditions being randomized; therefore it is not influenced by any other factor (Howitt and Cramer, 2011)
The pros regarding true experiments are that the