the experimental method

• whenever you conduct research you must always carefully consider ethical issues and related matters
• never use anyone under the age of 16 as a participant (or in fact any people who may be described as 'vulnerable' in any way)
• always obtain informed consent from all participants tell your participant what they will be expected to do and allow them to refuse to take part
• debrief your participants after the study to tell them of any deception and to allow them to withdraw their data if they object on reflection, to having taken part, before beginning any study consult w/ others on the 'script' you will use for the informed consent and the debrief
• systematic study of human behaviour you followed the scientific method: observe -> state expectations -> design a study -> see if your expectations were correct
• psychologists use special words to identify aspects of the research process, we have already used some of the terms in this book and most of them are probably familiar to you from using them in science
• what will you measure? = this is called the dependent variable (DV) when you decided exactly what you would measure you operationalised the DV it isn't enough just to get people to do 'some work' you should have made sure that all participants were doing the same task and would have specified what that task was (e.g. memory test)
• what are your 2 conditions? = this is called the independent variable (IV) there are often 2 conditions of the IV in this case having the TV turned on or off, in order to conduct an experiment we need to compare one condition (studying w/ the TV on) w/ another condition studying w/ the TV off
• what are your 2 conditions? = these 2 conditions are described as different levels of the IV, a good study and good hypothesis should always include 2 (or more) levels of the IV, if we don't have these different conditions or levels we have no basis for comparison
• what are your 2 conditions? = so the hypothesis might be = students who do a memory task w/ the TV on produce work which gets fewer marks than those who do the same w/o the TV on
• what will you expect to find? = this is the hypothesis - a statement of what you believe to be true, your hypothesis might be something like = students who do a memory task w/ the TV on produce work which gets fewer marks
• hypothesis: this is different to the aims of the experiment the aims would be to investigate the effect of TV on the work a student produces, aims are intentions or possibly a research question (does noise affect the quality of work?) whereas a hypothesis is a statement of the relationship between the independent and dependent variable
• what will the participants do? = you worked out a set of standardised procedures, it is important to make sure that each participant did exactly the same thing in each condition otherwise the results might vary because of changes in procedure rather than because of the IV, such identical procedures are described as 'standardised'
• what do you need to control? = you will have tried to control some extraneous variables such as time of day (people might be better on a test in the morning than in the afternoon, so all participants should do a test at about the same time of day)
• the main characteristic of an experiment is that there is an IV which is deliberately changed (TV on or not) to see if this has any effect on the DV (quality of work), this permits us to draw casual conclusions we can make a statement about whether having the TV on or off causes a change in quality of work that is done because we can compare the effect of the 2 levels of the IV