Reading “A Handbook for Biological Investigation.”

Reading “A Handbook for Biological

Investigation.”

Yes….. I expect you to read it!Maybe more than once!

No tests No quizzes Performance only: You must know the

information and use it – like a reference book!

Use This While You Read

◦What is Science?◦What are the limitations of science?◦What are the underlying assumptions of science?

◦Re-read it now and then continue.

Ch 1 Read the chapter thinking about the following ideas.

Science is a process by which observations lead to hypothesis. (inductive logic step)

Hypotheses are then tested through deductive logic (cause and effect)

Rejected hypotheses make way for more research.

Accepted hypotheses support, but DO NOT prove, ideas about how the world works.

Science always leads to new questions, which must be tested!

What is science?

Science can only study natural phenomena.

Science cannot make moral judgments

What are the limitations of Science?

All phenomena are natural The natural world works via cause

and effect relationships The study of small populations allows

us to generalize about larger population behavior. (this is actually one of the most controversial or the ideas.)

What are the underlying assumptions of science?

Focuses on the natural world Aims to explain the natural world Uses testable ideas Relies on evidence Involves the scientific community Leads to ongoing research Benefits from scientific behavior

Science Checklist: Criteria for Science

◦Where are the things we can study?◦Broad vs. Narrow questions Do broad questions require simple or complex studies?

Should we study broad or narrow questions?

Ch 2 Re-read thinking about these main ideas!

Anything you are interested in can be studied if you properly develop questions into hypothesis. PASSION ASSIGNMENT

We are encouraging you to focus on narrow questions because larger questions require more complex design and analysis.

Ch 2 Experiments are everywhere!

◦What are the types of measurement scales?

◦Distinguish between nominal and ordinal scales.

◦Distinguish between ratio and interval scales.

◦Distinguish discrete data from continuous data.

◦Why is it important to know what type of data you are collecting?

Ch 3 Re-read thinking about the following:

Discrete Data - count data, answers questions about how many and how frequent. i.e. distributions of colors in a population of cats.◦ Nominal – unranked categories. ◦ Ordinal - ranked categories.

Continuous data – data measured on a scale. Answers questions about correlations, means, std. deviation, etc.◦ Interval – no true zero point (i.e. arbitrary zero

point) I.e. Celsius.◦ Ratio – actual zero point ie: Kelvin scale

What are the types of measurement scales? More about this later!

Most Information Least Information Ratio scale & Interval scale: Both of these can discuss correlations between the variables

Ordinal scale & discrete scale: These have less information & can only identify distributions within a population (how frequent or how many

Information theory and types of data

The type of data you are collecting effects what type of answers you can find.

Must collect data that is appropriate to answer the questions you ask.

Correlations can only be studied with measurement data

Differences can be studied with any of these data types.

Why is it important to know what type of data you are collecting?

◦Frequency histograms◦Mean, median and mode◦Normal distributions◦Most importantly, that distributions within populations tend to be centered around a central value.

Ch 4. Re –read it considering the following ideas:

◦Why is it important to understand the spread of the data and not just the central tendency?

◦How do we measure the spread and what does it tell us?

◦Define variance and standard deviation.

CH.5 Re-read considering the following:

Variance and standard deviation are very important because they quantify the spread of the data and allow us to compare two populations. You need to understand this more so check these links that might help.

http://www.mathsisfun.com/standard-deviation.html

http://sciencepolicy.colorado.edu/students/envs_5120/statistics_2_6.pdf

Ch 5. Some thoughts

◦What is the null hypothesis? hypothesis that states there is no difference/ correlation between the variables

◦What is the change hypothesis? hypothesis that states there is a difference/ correlation between the variables

CH 6: Re-read considering the following:

1. Determine your question 2. Consider what type of data the

question needs3. Define the variables you are

studying4. Write your hypothesis5. Set up data tables6. Align data collection with statistical

test

CH 6. What is a proper order for designing experiments?

Notice only after all of this pre-work can you even hope to write a procedure.

Remember the procedure has only one function; to collect good data!

You cannot write or execute a procedure without a strong understanding of what your data will look like.

Now You Can Determine Your Materials ……

• What is the difference between correlation and difference testing?

• How much difference is necessary to say two populations are different?

• What is a confidence interval?• What is the difference between parametric and nonparametric tests?

• When do you reject the change hypothesis?

• When do you reject the null hypothesis?

CH 7 Re-read this chapter focusing on the following:

This is one of our focus topics during the class. Do your best to understand it and the first several days will include lectures on this topic.

Cannot experiment without determining your method of data analysis

Red flag: Here is my data. What statistical test do I use? Then I know you did not do slide # 17!!

CH 7: the Heart of Data Analysis