# S-Cool Revision Summary

## S-Cool Revision Summary

 Hypothesis A precise, testable statement or prediction about the expected outcome of an investigation. Null hypothesis prediction One that states results are due to chance and are not significant in terms of supporting the idea being investigated. Research hypothesis prediction One that states that results are not due to chance and that they are significant in terms of supporting the idea being investigated. One-tailed hypothesis A directional hypothesis. Two-tailed hypothesis One in which the direction of results is not predicted. Random sampling Everyone in the entire target population has an equal chance of being selected. Opportunity sampling Uses people from target population available at the time. Systematic sampling Chooses subjects in a systematic way. Self-selected sample Participants volunteer. Stratified sampling Divides target population into groups, people in sample from each group in same proportions as population. Counterbalancing Alternating the order in which participants perform in different conditions of an experiment. Randomisation Material for each condition in an experiment is presented in a random order, this is also to prevent order effects. Single-blind design Participants do not know which condition (experimental or control) they are in. Double-blind design Neither the participants nor the experimenter know which condition people are being treated to. Time sampling Observations may be made at regular time intervals and coded. Event sampling Keep a tally chart of each time a type of behaviour occurs. Point sampling Focus on one individual at a time for set period of time. Quantitative research Gathers data in numerical form and is concerned with making 'scientific' measurements. Quantitative data analysis uses a barrage of inferential statistical tests. Qualitative research Gathers information that is not in numerical form. Arithmetic mean All values in a set of data are added together and divided by the number of values (N). Median All values are arranged in order, the middle value is the median. Mode The most frequent value or score in a set of data. Range Simple measure of dispersion- shows the total spread of data.