RESEARCH METHODS MIDTERM -
MCPHS SPRING
null hypothesis (H0) - the statistical hypothesis tested by the statistical procedure; usually a
hypothesis of no difference or no relationship
Interquartile Range (IQR) - the difference between the first and third quartiles (middle 50% of
observations)
dichotomous measure - describes the presence or absence of an attribute (ex smoker/non-
smoker)
nominal data - categories that vary with no natural order (ex blood types)
ordinal data - categories with natural order but without clear units (ex severe vs mild symptoms)
what are the types of categorical (qualitative) data? - nominal and ordinal
what are the types of numerical (quantitative) data? - discrete and continuous
discrete data - data that can only take certain values (ex whole numbers)
continuous data - data that can take any value (ex decimals)
mean - average value; sum of all observations / # of observations
median - middle value; 50th percentile
mode - most common value
, range - difference between the highest and lowest values in a distribution
standard deviation - a measure of spread or variability about the mean
n- sample size
X (bar) - sample mean
s- sample size standard deviation
N- population size
μ- population mean
σ- population standard deviation
empirical rule - gives approximate percentage of values that fall within plus or minus 1(68), 2(95)
and 3(99.7) standard deviations
standard error of the mean - the standard deviation of the sampling distribution of sample means
confidence interval - the range of values within which a population parameter is estimated to lie
p value - the probability level which forms basis for deciding if results are statistically significant
parameters - true values that are constant
MCPHS SPRING
null hypothesis (H0) - the statistical hypothesis tested by the statistical procedure; usually a
hypothesis of no difference or no relationship
Interquartile Range (IQR) - the difference between the first and third quartiles (middle 50% of
observations)
dichotomous measure - describes the presence or absence of an attribute (ex smoker/non-
smoker)
nominal data - categories that vary with no natural order (ex blood types)
ordinal data - categories with natural order but without clear units (ex severe vs mild symptoms)
what are the types of categorical (qualitative) data? - nominal and ordinal
what are the types of numerical (quantitative) data? - discrete and continuous
discrete data - data that can only take certain values (ex whole numbers)
continuous data - data that can take any value (ex decimals)
mean - average value; sum of all observations / # of observations
median - middle value; 50th percentile
mode - most common value
, range - difference between the highest and lowest values in a distribution
standard deviation - a measure of spread or variability about the mean
n- sample size
X (bar) - sample mean
s- sample size standard deviation
N- population size
μ- population mean
σ- population standard deviation
empirical rule - gives approximate percentage of values that fall within plus or minus 1(68), 2(95)
and 3(99.7) standard deviations
standard error of the mean - the standard deviation of the sampling distribution of sample means
confidence interval - the range of values within which a population parameter is estimated to lie
p value - the probability level which forms basis for deciding if results are statistically significant
parameters - true values that are constant
