Y1 PPGH DEFINITIONS EXAM WITH
COMPLETE SOLUTION
Variable - Answer Quantity with a value to quality that can vary
Random variation - Answer Differences between variables governed by chance
Nominal data - Answer Consists of simple labels/categories with no order
Ordinal Data - Answer Consists of categories with a natural order
Metric Data - Answer Consists of precisely defines values
All spaces between adjacent values are the same
Qualitative - Answer Nominal and ordinal values
Quantitative - Answer Counting or measuring - numbers
Proportions - Answer Ratio in which numerator is included in denominator - %
Numerator - Answer Upper portion of a fraction
Denominator - Answer Lower portion of a fraction - population at risk in the calculation
Person Time - Answer Combines persons and time as the denominator in
incidence/mortatilty rates - when people are at risk of dying for varying periods
Ratios - Answer Compares frequencies of categories
Rate - Answer Measure of the frequency of the occurrence of a phenomenon
Normal Distribution - Answer Smooth symmetrical bell shaped curve
Mode - Answer Value that occurs most frequently
Median - Answer Middle value after arranged in ascending order
Mean - Answer Sum of all / number of values
Skewness - Answer Measurement of asymmetry
-ve skew = to the right
+ve skew = to the left
Variance - Answer Measure of the spread of values away from the mean
Range - Answer Difference between largest and smallest values
, Interquartile range - Answer Difference between lowest 25% and highest 25% of values
Semi-quartile range - Answer Average distance of the 1st and 3rd quartiles from the
mean
Standard deviation - Answer Degree of variation in a set of data values, relative to the
mean
Standard Error - Answer Measure of the deviation of the sample mean from the true
population mean (big samples reduce standard error)
Confidence interval - Answer Range that is likely to contain the true population value
Null Hypothesis - Answer No difference between the groups being tested
Type I error - Answer A difference is found when there isn't one - Wrongly reject a true
null hypothesis
Type II error - Answer No difference is found when one exists - Wrongly accepting a
false null hypothesis
Power - Answer Probability that a study will detect a statistically significant difference
P values - Answer How likely it is that a hypothesis is true
Regression Coefficient - Answer Describes the relationship between 2 variables
- Slope of the line of best fit on a graph
Correlation coefficient - Answer Linear relationship between 2 values - the strength of
this relationship
Parametric tests - Answer Compare samples of normal distribution
T test - Answer Compares 2 samples to test probability that samples come from a
population with the same mean
Chi Squared Test - Answer Measures the difference between actual and expected
frequencies
Case study - Answer One case report
Case series - Answer Series of case reports
Correlation study - Answer Study of relationship between 2 values
Cross-sectional study - Answer Measures outcomes at a single point in time for a
number of individuals
- Survey
Case-Control Study - Answer Retrospective study with groups chosen on the basis of
COMPLETE SOLUTION
Variable - Answer Quantity with a value to quality that can vary
Random variation - Answer Differences between variables governed by chance
Nominal data - Answer Consists of simple labels/categories with no order
Ordinal Data - Answer Consists of categories with a natural order
Metric Data - Answer Consists of precisely defines values
All spaces between adjacent values are the same
Qualitative - Answer Nominal and ordinal values
Quantitative - Answer Counting or measuring - numbers
Proportions - Answer Ratio in which numerator is included in denominator - %
Numerator - Answer Upper portion of a fraction
Denominator - Answer Lower portion of a fraction - population at risk in the calculation
Person Time - Answer Combines persons and time as the denominator in
incidence/mortatilty rates - when people are at risk of dying for varying periods
Ratios - Answer Compares frequencies of categories
Rate - Answer Measure of the frequency of the occurrence of a phenomenon
Normal Distribution - Answer Smooth symmetrical bell shaped curve
Mode - Answer Value that occurs most frequently
Median - Answer Middle value after arranged in ascending order
Mean - Answer Sum of all / number of values
Skewness - Answer Measurement of asymmetry
-ve skew = to the right
+ve skew = to the left
Variance - Answer Measure of the spread of values away from the mean
Range - Answer Difference between largest and smallest values
, Interquartile range - Answer Difference between lowest 25% and highest 25% of values
Semi-quartile range - Answer Average distance of the 1st and 3rd quartiles from the
mean
Standard deviation - Answer Degree of variation in a set of data values, relative to the
mean
Standard Error - Answer Measure of the deviation of the sample mean from the true
population mean (big samples reduce standard error)
Confidence interval - Answer Range that is likely to contain the true population value
Null Hypothesis - Answer No difference between the groups being tested
Type I error - Answer A difference is found when there isn't one - Wrongly reject a true
null hypothesis
Type II error - Answer No difference is found when one exists - Wrongly accepting a
false null hypothesis
Power - Answer Probability that a study will detect a statistically significant difference
P values - Answer How likely it is that a hypothesis is true
Regression Coefficient - Answer Describes the relationship between 2 variables
- Slope of the line of best fit on a graph
Correlation coefficient - Answer Linear relationship between 2 values - the strength of
this relationship
Parametric tests - Answer Compare samples of normal distribution
T test - Answer Compares 2 samples to test probability that samples come from a
population with the same mean
Chi Squared Test - Answer Measures the difference between actual and expected
frequencies
Case study - Answer One case report
Case series - Answer Series of case reports
Correlation study - Answer Study of relationship between 2 values
Cross-sectional study - Answer Measures outcomes at a single point in time for a
number of individuals
- Survey
Case-Control Study - Answer Retrospective study with groups chosen on the basis of
