Xã hội học - Basic analytical techniques

Basic Analytical TechniquesSamuel K. Frimpong (Ph.D.)Outline presentationDescriptive Statisticst/z testANOVACorrelationRegressionDescriptive StatisticsCentral tendenciesVariability and dispersionShape and positionSpecific valuesPercentiles and RanksCountCentral TendenciesMean Arithmetic (AVERAGE)Geometric (GEOMAN)Harmonic (HARMEAN)Trimmed (TRIMMEAN)Median (MEDIAN)Mode (MODE)NB: Words in parentheses are excel commandsVariability and DispersionMean average deviation (AVDEV)Squared deviation (DEVSQ)Sample Standard deviation (STDEV)Population standard deviation (STDEVP)Sample variance (VAR)Population variance (VARP)RangeShapes and PositionKurtosis (KURT)Skewness (SKEW)Standardized value or z-score (STANDARDIZE)Specific valuesMaximum (MAX)Minimum (MIN)Kth LargestKth SmallestPercentiles and RanksNth Percentile (PERCENTILE)Quartile (QUARTILE)Rank (RANK)Percentage rank (PERCENTRANK)CountingCount of cells containing numbers (COUNT)Count of cells not blank (COUNTA)Frequency (FREQUENCY)Permutation (PERMUT)t/Z testst-test is used to compare means between two small samplesTwo samples assuming equal variancesTwo samples assuming unequal variancesPaired two samplesZ-test is used to compare means between two large samplesANOVAAnalysis of Variance (ANOVA) is used to examine statistical difference between means of two or more groups.e.g. MBA Accounting Regular MBA Accounting Evening MBA Accounting WeekendOne-way ANOVATwo-way ANOVACorrelationCorrelation is used to examine the association between two metric variables. The strength of the association is measured by the correlation coefficient.Correlation Coefficients + 1.0 0.0 Zero Correlation = the value of Y does not increase or decrease with the value of X. - 1.0Positive Correlation = when the value of X increases, the value of Y also increases. When the value of X decreases, the value of Y also decreases. Negative Correlation = when the value of X increases, the value of Y decreases. When the value of X decreases, the value of Y increases. Rule of thumb for interpretation Range of Coefficient Strength of Association+/– .91 to +/– 1.00 Very Strong+/– .71 to +/– .90 High+/– .41 to +/– .70 Moderate+/– .21 to +/– .40 Small+/– .01 to +/– .20 SlightRegressionRegression is used to establish causal relationships between dependent variable and independent variable(s)Simple or bivariate regressionMultiple regressionFor Further ReadingClassification of Statistical Techniques