Biostatistics Exam Study Guide
Exam 1
Chapter 1 * In statistics the group we wish to study is called the population * A sample is a subset of the population which is used to gain insight about the population. Samples are used to represent a larger group, the population. * • Descriptive statistics – the collection, organization, analysis, and presentation of data. * Inferential statistics – uses descriptive statistics to estimate population parameters; an educated guess about the population based on sample data.
Chapter 2 * • During the experiment a treatment is applied to the experimental group. * • The exact treatment will depend on the particular experiment. * • The treatment changes the level of the explanatory variable in the experiment. The effect of the treatment can be measured by comparing the response variable in the control and experimental groups. * Qualitative: Descriptions and Labels * Quantitative: counts and measurements * Discrete: Usually counts of things, restricted set of values * Continuous: Usually measurements, data can take on any value in an interval * Nominal measures offer names or labels for certain characteristics * Ordinal data represents data in an associated order. * If the data can be ordered and the arithmetic difference is meaningful, the data is interval. * Ratio data has a meaningful zero point and the ratio of two data points is meaningful. * Quantitative data is measured on the interval or ratio scale. * Qualitative data is measured on a nominal or ordinal scale
Chapter 3 * A frequency distribution is a summary technique that organizes data into classes and provides in tabular form a list of the classes along with the number of observations in each class * * * The cumulative relative frequency is the proportion of observations in a particular class and all preceding classes. Below is a cumulative relative frequency distribution for the heart rate data.
Chapter 1 * In statistics the group we wish to study is called the population * A sample is a subset of the population which is used to gain insight about the population. Samples are used to represent a larger group, the population. * • Descriptive statistics – the collection, organization, analysis, and presentation of data. * Inferential statistics – uses descriptive statistics to estimate population parameters; an educated guess about the population based on sample data.
Chapter 2 * • During the experiment a treatment is applied to the experimental group. * • The exact treatment will depend on the particular experiment. * • The treatment changes the level of the explanatory variable in the experiment. The effect of the treatment can be measured by comparing the response variable in the control and experimental groups. * Qualitative: Descriptions and Labels * Quantitative: counts and measurements * Discrete: Usually counts of things, restricted set of values * Continuous: Usually measurements, data can take on any value in an interval * Nominal measures offer names or labels for certain characteristics * Ordinal data represents data in an associated order. * If the data can be ordered and the arithmetic difference is meaningful, the data is interval. * Ratio data has a meaningful zero point and the ratio of two data points is meaningful. * Quantitative data is measured on the interval or ratio scale. * Qualitative data is measured on a nominal or ordinal scale
Chapter 3 * A frequency distribution is a summary technique that organizes data into classes and provides in tabular form a list of the classes along with the number of observations in each class * * * The cumulative relative frequency is the proportion of observations in a particular class and all preceding classes. Below is a cumulative relative frequency distribution for the heart rate data.