Psych 253 -EXAM PACK 2024

Two types of analyses that we conduct - Correct Answer 1. Descriptive statistics 2. inferential statistics What is inferential statistics? - Correct Answer drawing conclusions or making predictions about a population based on a sample of data by using statistical methods to infer information from a subset of data to larger, often unknown populations. identify significant differences or relationships Descriptive statistics fall into 2 types. what are they? - Correct Answer 1. Measures of central tendency 2. Measures of dispersion Define measures of central tendency and measures of dispersion (what processes are included in each) - Correct Answer 1. Measures of central tendency: - mean - mode - median 2. Measures of dispersion: - Range - Interquartile range - Standard deviation - Variance Advantage of the mean - Correct Answer resistant to differences across samples because it is calculated with all data points. What is important about the mode in terms of nominal and ordinal data? - Correct Answer The mode can be calculated for any level of data, including ordinal and nominal data. What is it called when you have this many modes: 1. one 2. two 3. three 4. four + - Correct Answer 1. uni-modal 2. bi-modal 3. tri-modal 4. multi-modal Why and how is the median sometimes used with reaction time data? - Correct Answer The median is not affected by outlying scores, so used in reaction times when you can have extreme data points that reflect large differences in reaction times Why can both the median and mode be of limited use if you want to compare your findings with averages in other studies? - Correct Answer They are of limited use when you want to compare your findings with other studies as they are based on just one single data point within the entire data set. Unlike the mean calculation of mean - Correct Answer u = EX / N What do measures of dispersion tell us? - Correct Answer Measures of dispersion tell us how homogenous or heterogenous the variable is. (how scattered or squeezed the values are). help in understanding the data variation around the central value What is the interquartile range? - Correct Answer The interquartile range is the difference between the 75th percentile and the 25th percentile (3rd and 1st quarter). what are the formulas for standard deviation - Correct Answer SD = square root of variance OR SD^2 = variance in words, what is the formula for standard deviation - Correct Answer standard deviation is the square root of the sum of squared deviations from the mean divided by the number of observations What does the standard deviation and variance tell you? - Correct Answer They both tell you how widely distributed the raw data points are around the mean What does a standard deviation of 0 mean? - Correct Answer A standard deviation close to 0 means that the observations are close to the mean. when is SD not very useful? - Correct Answer when looking at data that is not normally distributed What are the 2 types of sampling - Correct Answer convenience sampling and random sampling What is another phrase for Hypothesis testing? - Correct Answer Null Hypothesis Significance Testing (NHST) we test our null hypothesis to see if we a)_____ the null hypothesis of no effect, or whether we b)___________ it and accept the alternative hypothesis - Correct Answer a) accept b) reject what is the relationship between statistical significance and a Type 1 error - Correct Answer Statistical significance s