knowt logo

Class 8 Measurement 2020 Sp

Measurement & Statistics

Measurement

  • Measurement involves assigning values to outcomes.

  • Examples of measurement include percentages, numerical values like 9.3 mg/dl, and categorical distinctions like high vs. low social class.

Levels of Measurement

  • Nominal level assigns names or categories.

  • Ordinal level assigns categories with order.

  • Interval level includes equal intervals between categories.

  • Ratio level has equal intervals and an absolute zero point.

Statistics Overview

  • Descriptive statistics describe data characteristics.

  • Inferential statistics draw conclusions from data for broader applications.

  • Power calculations, such as determining sample size, are essential in statistical analysis.

Descriptive Statistics

  • Descriptive statistics cover data distribution, variance, central tendency measures (mean, median, mode), and variability around the mean.

Inferential Statistics

  • Inferential statistics involve confidence intervals, types of errors (Type I and Type II), and statistical tests like T-tests, ANOVAs, correlations, regressions, and relative risk analysis.

Confidence Intervals

  • Confidence intervals indicate a range of values that likely includes the true population mean.

  • They are expressed with a confidence level (e.g., 95%) and upper and lower limits.

Types of Error

  • Type I error involves falsely rejecting the null hypothesis.

  • Type II error occurs when the null hypothesis is not rejected despite an actual difference.

  • Power is the probability of avoiding a Type II error.

T Tests

  • T tests compare means of two groups and determine statistical significance through p-values.

  • A significance level (α) is typically set at 0.05, with p ≤ 0.05 indicating a significant difference.

ANOVAs

  • Analysis of variance (ANOVA) compares means of three or more groups, offering a more robust alternative to multiple t-tests.

  • Various ANOVA tests exist based on data types and shapes.

Correlations

  • Correlations measure relationships between variables, with the coefficient (r) ranging from -1.0 to +1.0.

  • The strength and direction of the relationship are indicated by the correlation coefficient.

Regressions

  • Regression models the relationship between dependent and independent variables.

  • R2 value describes how well the regression line fits the data, ranging from 0.0 to 1.0.

Relative Risk

CP

Class 8 Measurement 2020 Sp

Measurement & Statistics

Measurement

  • Measurement involves assigning values to outcomes.

  • Examples of measurement include percentages, numerical values like 9.3 mg/dl, and categorical distinctions like high vs. low social class.

Levels of Measurement

  • Nominal level assigns names or categories.

  • Ordinal level assigns categories with order.

  • Interval level includes equal intervals between categories.

  • Ratio level has equal intervals and an absolute zero point.

Statistics Overview

  • Descriptive statistics describe data characteristics.

  • Inferential statistics draw conclusions from data for broader applications.

  • Power calculations, such as determining sample size, are essential in statistical analysis.

Descriptive Statistics

  • Descriptive statistics cover data distribution, variance, central tendency measures (mean, median, mode), and variability around the mean.

Inferential Statistics

  • Inferential statistics involve confidence intervals, types of errors (Type I and Type II), and statistical tests like T-tests, ANOVAs, correlations, regressions, and relative risk analysis.

Confidence Intervals

  • Confidence intervals indicate a range of values that likely includes the true population mean.

  • They are expressed with a confidence level (e.g., 95%) and upper and lower limits.

Types of Error

  • Type I error involves falsely rejecting the null hypothesis.

  • Type II error occurs when the null hypothesis is not rejected despite an actual difference.

  • Power is the probability of avoiding a Type II error.

T Tests

  • T tests compare means of two groups and determine statistical significance through p-values.

  • A significance level (α) is typically set at 0.05, with p ≤ 0.05 indicating a significant difference.

ANOVAs

  • Analysis of variance (ANOVA) compares means of three or more groups, offering a more robust alternative to multiple t-tests.

  • Various ANOVA tests exist based on data types and shapes.

Correlations

  • Correlations measure relationships between variables, with the coefficient (r) ranging from -1.0 to +1.0.

  • The strength and direction of the relationship are indicated by the correlation coefficient.

Regressions

  • Regression models the relationship between dependent and independent variables.

  • R2 value describes how well the regression line fits the data, ranging from 0.0 to 1.0.

Relative Risk