BIOLOGY FOR LIFE
  • Syllabus
    • Core >
      • 1: Cell Biology >
        • 1.1: Introduction to Cells
        • 1.2: Ultrastructure of Cells
        • 1.3: Membrane Structure
        • 1.4: Membrane Transport
        • 1.5: The Origin of Cells
        • 1.6: Cell Division
      • 2: Molecular Biology >
        • 2.1: Molecules to Metabolism
        • 2.2: Water
        • 2.3: Carbohydrates and Lipids
        • 2.4: Proteins
        • 2.5: Enzymes
        • 2.6: DNA and RNA
        • 2.7: DNA Replication, Transcription and Translation
        • 2.8: Cell Respiration
        • 2.9: Photosynthesis
      • 3: Genetics >
        • 3.1: Genes
        • 3.2: Chromosomes
        • 3.3: Meiosis
        • 3.4: Inheritance
        • 3.5: Genetic Modification and Biotechnology
      • 4: Ecology >
        • 4.1: Species, Communities and Ecosystems
        • 4.2: Energy Flow
        • 4.3: Carbon Cycling
        • 4.4: Climate Change
      • 5: Evolution and Biodiversity >
        • 5.1: Evidence for Evolution
        • 5.2: Natural Selection
        • 5.3: Classification and Biodiversity
        • 5.4: Cladistics
      • 6: Human Physiology >
        • 6.1: Digestion and Absorption
        • 6.2: The Blood System
        • 6.3: Defense Against Infectious Disease
        • 6.4: Gas Exchange
        • 6.5: Neurons and Synapses
        • 6.6: Hormones, Homeostasis and Reproduction
    • Higher Level >
      • 7: Nucleic Acids >
        • 7.1: DNA Structure and Replication
        • 7.2: Transcription and Gene Expression
        • 7.3: Translation
      • 8: Metabolism, Cell Respiration & Photosynthesis >
        • 8.1: Metabolism
        • 8.2: Cell Respiration
        • 8.3: Photosynthesis
      • 9: Plant Biology >
        • 9.1: Transport in the Xylem of Plants
        • 9.2: Transport in the Phloem of Plants
        • 9.3: Growth in Plants
        • 9.4: Reproduction in Plants
      • 10: Genetics and Evolution >
        • 10.1: Meiosis
        • 10.2: Inheritance
        • 10.3: Gene Pools and Speciation
      • 11: Animal Physiology >
        • 11.1: Antibody Production and Vaccination
        • 11.2: Movement
        • 11.3: Kidney and Osmoregulation
        • 11.4: Sexual Reproduction
    • Options >
      • D: Human Physiology >
        • D.1: Human Nutrition
        • D.2: Digestion
        • D.3: Functions of the Liver
        • D.4: The Heart
        • D.5: Hormones and Metabolism
        • D.6: Transport of Respiratory Gases
  • IB Requirements
    • Learner Profile
    • Group 4 Project
    • External Exam
    • Internal Assessment >
      • Personal Engagement
      • Exploration
      • Analysis
      • Evaluation
      • Communication
    • Extended Essay
  • Investigation Skills
    • Lab Safety
    • Microscopy
    • Lab Drawings
    • Data Tables
    • Measurement
    • Statistics >
      • Descriptive Statistics >
        • Skew
        • Measures of Central Tendancy
        • Measures of Spread
        • Pearson Correlation
      • Inferential Statistics >
        • T-Test
        • ANOVA
        • Kruskal-Wallis
        • X2 Test for Independence
        • X2 Goodness of Fit
    • Graphing >
      • Graphing with Excel
      • Interpreting Error Bars
    • Error Analysis
  • Course Info
    • Above & Beyond >
      • Biology Club
      • Pumpkin Carving
      • Scavenger Hunt
      • Science News
      • IB Bio Dance
      • Wood Duck Project
      • Invasive Crayfish Project
    • Assessment >
      • Class Grading IB Bio I
      • Class Grading IB Bio II
      • Daily Quizzes
      • Lab Practicals
    • Class Photos
    • Recommendations
    • Supplemental Reading
  • Contact
  • About
    • Philosophy
    • Resume
    • Reflection
    • Site Feedback
    • Favorite Quotes
    • AEF Blog
  • Expeditions
    • Bahamas (2009)
    • Trinidad (2010)
    • Trinidad (2011)
    • Ecuador (2012)
    • Trinidad (2013)
    • Peru (2014)
    • Bahamas (2015)
    • Peru (2016)
    • Costa Rica (2017)
    • Costa Rica (2018)
    • Arizona (2022)
    • Florida (2023)
  • Summer Ecology Research

Statistical Analysis

Descriptive Statistics

Descriptive statistics help to summarize data.   Descriptive statistics do not allow you to make conclusions beyond the data you have collected or reach conclusions regarding any hypotheses you might have made. They are simply a way to describe your data.  Descriptive statistics are very important because if you simply presented your raw data it would be hard to visualize what the data was showing, especially if there was a lot of it.

Common descriptive statistics used in IB Biology are:
  • Skew
  • Measures of central tendency (mean, median or mode)
  • Measures of Spread (range, standard deviation or  quartiles)
  • Correlation coefficient

Inferential Statistics

Inferential statistics are mathematical calculations performed to determine if the results from your sample of data are likely due to chance or are a true representation of the population. Inferential statistics are used to determine the probability of chance alone leading to your sampled results.  More about inferential statistics is available here.  

Common descriptive statistics used in IB Biology are: 
  • T-Test 
  • ANOVA 
  • Kruskal-Wallis 
  • Chi-Square Goodness of Fit 
  • Pearson's Correlation (bottom of the page) 
  • Spearman's Rank Correlation
  • ​Chi-Square Test of Independence

Students in IB biology are expected to have acquired competence in the areas of mathematics set out below in order to develop the knowledge, understanding and skills in the subject content.  All IB biology students should be able to:
  • Perform the basic arithmetic functions: addition, subtraction, multiplication and division.
  • Recognize basic geometric shapes.
  • Carry out simple calculations within a biological context involving means, decimals, fractions, percentages, ratios, approximations, reciprocals and scaling.
  • Use standard and scientific notation.
  • Recognize direct and inverse proportion.
  • Represent and interpret frequency data in the form of bar charts, column graphs, histograms and pie charts.
  • Determine the mean, mode and median of a set of data.
  • Plot and interpret graphs (with suitable scales and axes) involving two variables which show linear or non-linear relationships.
  • Plot and interpret scatter graphs to identify a correlation between two variables, and appreciate that the existence of a correlation does not establish a causal relationship.
  • Demonstrate sufficient knowledge of probability to understand how Mendelian ratios arise and to calculate such ratios using a Punnett grid.
  • Recognize and use the relationships between length, surface area and volume.​
I give many of my IB Biology resources away, for the benefit of students and teachers around the world. 
If you've found the materials helpful, please consider making a contribution of any amount
to 
this Earthwatch Expedition Fund. 

​Did I forget something?  Know of a mistake? Have a suggestion?  Let me know by emailing me here.

Before using any of the files available on this site,
​please familiarize yourself with the 
Creative Commons Attribution License. 
​​​It prohibits the use of any material on this site for commercial  purposes of any kind.  ​


"When we try to pick out anything by itself, we find it hitched to everything else in the Universe." 
 John Muir,   1911
  • Syllabus
    • Core >
      • 1: Cell Biology >
        • 1.1: Introduction to Cells
        • 1.2: Ultrastructure of Cells
        • 1.3: Membrane Structure
        • 1.4: Membrane Transport
        • 1.5: The Origin of Cells
        • 1.6: Cell Division
      • 2: Molecular Biology >
        • 2.1: Molecules to Metabolism
        • 2.2: Water
        • 2.3: Carbohydrates and Lipids
        • 2.4: Proteins
        • 2.5: Enzymes
        • 2.6: DNA and RNA
        • 2.7: DNA Replication, Transcription and Translation
        • 2.8: Cell Respiration
        • 2.9: Photosynthesis
      • 3: Genetics >
        • 3.1: Genes
        • 3.2: Chromosomes
        • 3.3: Meiosis
        • 3.4: Inheritance
        • 3.5: Genetic Modification and Biotechnology
      • 4: Ecology >
        • 4.1: Species, Communities and Ecosystems
        • 4.2: Energy Flow
        • 4.3: Carbon Cycling
        • 4.4: Climate Change
      • 5: Evolution and Biodiversity >
        • 5.1: Evidence for Evolution
        • 5.2: Natural Selection
        • 5.3: Classification and Biodiversity
        • 5.4: Cladistics
      • 6: Human Physiology >
        • 6.1: Digestion and Absorption
        • 6.2: The Blood System
        • 6.3: Defense Against Infectious Disease
        • 6.4: Gas Exchange
        • 6.5: Neurons and Synapses
        • 6.6: Hormones, Homeostasis and Reproduction
    • Higher Level >
      • 7: Nucleic Acids >
        • 7.1: DNA Structure and Replication
        • 7.2: Transcription and Gene Expression
        • 7.3: Translation
      • 8: Metabolism, Cell Respiration & Photosynthesis >
        • 8.1: Metabolism
        • 8.2: Cell Respiration
        • 8.3: Photosynthesis
      • 9: Plant Biology >
        • 9.1: Transport in the Xylem of Plants
        • 9.2: Transport in the Phloem of Plants
        • 9.3: Growth in Plants
        • 9.4: Reproduction in Plants
      • 10: Genetics and Evolution >
        • 10.1: Meiosis
        • 10.2: Inheritance
        • 10.3: Gene Pools and Speciation
      • 11: Animal Physiology >
        • 11.1: Antibody Production and Vaccination
        • 11.2: Movement
        • 11.3: Kidney and Osmoregulation
        • 11.4: Sexual Reproduction
    • Options >
      • D: Human Physiology >
        • D.1: Human Nutrition
        • D.2: Digestion
        • D.3: Functions of the Liver
        • D.4: The Heart
        • D.5: Hormones and Metabolism
        • D.6: Transport of Respiratory Gases
  • IB Requirements
    • Learner Profile
    • Group 4 Project
    • External Exam
    • Internal Assessment >
      • Personal Engagement
      • Exploration
      • Analysis
      • Evaluation
      • Communication
    • Extended Essay
  • Investigation Skills
    • Lab Safety
    • Microscopy
    • Lab Drawings
    • Data Tables
    • Measurement
    • Statistics >
      • Descriptive Statistics >
        • Skew
        • Measures of Central Tendancy
        • Measures of Spread
        • Pearson Correlation
      • Inferential Statistics >
        • T-Test
        • ANOVA
        • Kruskal-Wallis
        • X2 Test for Independence
        • X2 Goodness of Fit
    • Graphing >
      • Graphing with Excel
      • Interpreting Error Bars
    • Error Analysis
  • Course Info
    • Above & Beyond >
      • Biology Club
      • Pumpkin Carving
      • Scavenger Hunt
      • Science News
      • IB Bio Dance
      • Wood Duck Project
      • Invasive Crayfish Project
    • Assessment >
      • Class Grading IB Bio I
      • Class Grading IB Bio II
      • Daily Quizzes
      • Lab Practicals
    • Class Photos
    • Recommendations
    • Supplemental Reading
  • Contact
  • About
    • Philosophy
    • Resume
    • Reflection
    • Site Feedback
    • Favorite Quotes
    • AEF Blog
  • Expeditions
    • Bahamas (2009)
    • Trinidad (2010)
    • Trinidad (2011)
    • Ecuador (2012)
    • Trinidad (2013)
    • Peru (2014)
    • Bahamas (2015)
    • Peru (2016)
    • Costa Rica (2017)
    • Costa Rica (2018)
    • Arizona (2022)
    • Florida (2023)
  • Summer Ecology Research