2_Introduction to Descriptive Statistics

Page 1: Introduction & Descriptive Statistics


Page 2: Learning Outcome

  • Understand about statistics

  • Identify types of statistics

  • Explain about descriptive statistics

  • Use SPSS to measure descriptive statistics


Page 3: Introduction to Statistics

  • Data examples from various months (not specific)

    • Various values mentioned but not clearly defined


Page 4: What Is Statistics?

  • Analyzing data to make inferences and draw conclusions

  • Key processes include:

    • Collecting

    • Describing

    • Interpreting


Page 5: Who Uses Statistics?

  • Widely used by:

    • Marketing

    • Accounting

    • Quality control

    • Consumers

    • Professional sports

    • Hospital administrators

    • Educators

    • Politicians

    • Researchers

    • Students


Page 6: Basic Terms Used in Statistics

  • Population: Set of individuals or events analyzed

  • Sample: Subset of a population representing the whole

  • Variable: Characteristic of interest for each element

  • Data: Values collected for the variable from elements of the sample


Page 7: Scale of Measurement

  • Categorical: Describes or categorizes

    • Nominal: No order (e.g., gender)

    • Ordinal: Ordered categories

  • Numerical: Quantifies elements

    • Interval: Arbitrary zero, can add or subtract

    • Ratio: Non-arbitrary zero, can multiply/divide


Page 8: Nominal Variable

  • Classifies characteristics into categories

  • Data categories are mutually exclusive and not ranked

  • Examples:

    • Gender

    • Dichotomous variables (e.g., patient status)


Page 9: Ordinal Variable

  • Incorporates ranking

  • Differences/distances between ranks are not quantifiable

  • Examples:

    • Socioeconomic status

    • Attitude scales


Page 10: Interval Variable

  • Quantitative scale (discrete/continuous)

  • Discrete: countable values (gaps)

  • Continuous: uncountable values (decimal values)

  • Zero point is arbitrary (e.g., temperature)


Page 11: Ratio Variable

  • Similar to interval but with a non-arbitrary zero

  • Allows multiplication/division

  • Examples:

    • Temperature in Kelvin

    • Blood pressure readings


Page 12: Study Variable

  1. Dependent Variable: Outcome being studied

  2. Independent Variable: Hypothesized to influence the outcome

    • Examples provided on sports and job satisfaction


Page 13: Classification of Statistics

  1. Descriptive Statistics:

    • Describes data from a study

    • Includes tables, graphs, etc.

  2. Inferential Statistics:

    • Draws broader conclusions from results

    • Generalizes population characteristics from sample data


Page 14: Comparison of Statistics

  • Key concepts introduced include:

    • Population

    • Sample

    • Sampling technique

    • Descriptive and inferential statistics


Page 15: Descriptive Statistics

  • Overview of the topic


Page 16: Types of Categorical Variables

  • Frequency analysis using bar charts

  • Numerical variables: central tendency and variability measures


Page 17: Frequency Presentation

  • Frequency distribution visualizations (bar charts)


Page 18: Frequency Table

  • Displays values paired with frequency

  • May include cumulative and relative frequency


Page 19: Generating Frequency Table Using JAMOVI

  • Instructions for using JAMOVI for data analysis presented


Page 20: Example Frequency Table (JAMOVI Output)

  • Displays frequency of gender


Page 21: APA 7th Style Frequency Table

  • Structure of presenting results in APA format


Page 22: Categorical Variable Bar Graph

  • Graphical representation of frequencies for categorical data


Page 23: Bar Chart Specifications

  • Axes representations and bar detailing


Page 24: Types of Bar Charts

  • Different formats including stacked and clustered bars


Page 25: Generating Bar Graphs Using JAMOVI

  • Steps to create bar graphs through JAMOVI


Page 26: Gender Frequency Results

  • Summary of gender data in graph form


Page 27: Excellence Graph

  • Importance of clear data representation


Page 28: Numerical Variable Measures

  • Central tendency, variability, and graphical presentations defined


Page 29: Mean Calculation

  • Calculation of sample average with sensitivity explained


Page 30: Example Mean Calculation

  • Practical example calculating the mean from blood pressure values


Page 31: Median Definition

  • Explanation on finding the middle value of ordered data sets


Page 32: Example Odd Median Calculation

  • Provides an example with arranged basketball scores


Page 33: Example Even Median Calculation

  • Explanation through cigarette nicotine content data


Page 34: Mode Definition

  • Description of the mode and its significance in statistics


Page 35: Comparing Mean, Median, and Mode

  • Summary of respective scenarios for each measure's utility


Page 36: Calculate Mean, Median, Mode

  • Hands-on exercise with sample data provided


Page 37: Answers to Hands-on Exercise

  • Mean, median, mode calculations based on provided data


Page 38: Variance Definition

  • Description of variance in relation to observation spread


Page 39: Variance Example

  • Illustrated example with office equipment inventory


Page 40: Variance Example Calculation

  • Elaborate calculation providing insights on variance determination


Page 41: Standard Deviation Background

  • Definition and importance of standard deviation


Page 42: Standard Deviation Example

  • Calculation and illustration of scores given by judges


Page 43: Further Standard Deviation Calculation

  • Another example to solidify understanding


Page 44: Hands-On Exercise for Variance and Standard Deviation

  • Hands-on exercise prompts provided


Page 45: Hand-On Exercise Solutions

  • Provides calculations for variance and standard deviation


Page 46: Summary of Variance and Standard Deviation Computations

  • Key takeaway values from examples presented


Page 47: Range Explanation

  • Basics of calculating range for quick variability estimations


Page 48: Outlier Definition

  • Description of outliers in a dataset and their significance


Page 49: School Students Data

  • Sample data depicting student distribution in schools


Page 50: Data Mean and Standard Deviation Analysis

  • Analysis variations between different datasets


Page 51: Conclusion on Outlier Influence

  • Impact of outliers on mean and standard deviations


Page 52: Quartiles Overview

  • Introduction to quartiles and their significance in datasets


Page 53: Inter Quartile Range (IQR)

  • Definition and calculation of IQR for data dispersion assessment


Page 54: Example for Quartiles and IQR Calculation

  • Mathematics exercise involving student scores


Page 55: Calculation of Quartiles and IQR

  • Worked out example detailing quartiles with interpretations


Page 56: Further IQR Exploration

  • Continued emphasis on interpreting IQR findings


Page 57: Generating Summary Data Using JAMOVI

  • Overview of how JAMOVI handles summary data


Page 58: JAMOVI Output Summary

  • Specific statistics showcased in JAMOVI outputs


Page 59: APA 7th Style Results Reporting

  • Proper structuring of statistical reporting in APA format


Page 60: Standard Score (Z-score) Overview

  • Definition and utility of z-scores in statistics


Page 61: Z-score Example and Comparisons

  • Examples comparing two scores with respective z-scores


Page 62: Standard Normal Distribution Properties

  • Characteristics of normal distribution explained


Page 63: Area Under the Standard Normal Curve

  • Example of calculating area using z-scores


Page 64: Utility of Graphs

  • Importance of graphical data representation


Page 65: Histogram Explanation

  • Details concerning histograms and their properties


Page 66: Generating Histograms in JAMOVI

  • Steps to visualize data distributions via histograms


Page 67: Stem-and-Leaf Plot Explanation

  • Introduction to stem-and-leaf as a data visualization tool


Page 68: Stem-and-Leaf Example

  • Practical example constructing a stem-and-leaf display


Page 69: Displaying Stem-and-Leaf Data

  • Further detailing of the example constructed


Page 70: Additional Hands-On Exercise

  • Further practice with provided numerical values


Page 71: Additional Data Output Examining

  • Output analysis provided for hands-on tasks


Page 72: Box Plot Explanation

  • Box plots as a graphical display based on percentiles


Page 73: Box Plot Components

  • Details on components and interpretation of box plots


Page 74: Outlier Detection in Box Plots

  • Recognizing outliers within box plot data visualizations


Page 75: Scatter Plot Overview

  • Details on plotting bivariate data


Page 76: Scatter Plot Interpretation

  • Interpretation of data spread in scatter plots


Page 77: Closing Remarks

  • Thank you message for the presentation