The purpose of a research study can be expressed as an aim, research question of hypothesis.
Aim = the intended purpose of an investigation (what is is actually trying to discover)
hypotheses = a general prediction made at the outset of an experimental investigation about what the researcher expects to happen.
1. ALTERNATIVE HYPOTHESIS - predicts that something other than chance variation alone has played a part in producing the results obtained. Can be either directional or non-directional...
- A directional hypothesis predicts the direction in which results are expected to occur, e.g. 'more words are recalled from a list when using rehearsal as a mnemonic technique than when no mnemonic techinque is used'. Predicts no only tat there will be a difference, but also the direction of the difference.
- A non-directional hypothesis does not predict the expected direction of outcome, e.g. 'there is a difference in the number of words recalled from word lists presented with or without the presence of background music'. - difference is predicted but no prediction is made about the direction of the difference.
2. NULL HYPOTHESIS - predicts that the results of an experiment can be explained by chance variation alone rather than by the manipulation of the independent variable (IV).
e.g. In an experiment investigating the effect of a mnemonic on memory recall, the null hypothesis would predict no difference in the memory scores for the two conditions. If small…