WLF 448: Fish & Wildlife Population Ecology

II. SCIENTIFIC INVESTIGATION (Scimethd.cpl)

A. Introduction

B. Knowledge

1. Definition: Knowledge is defined as the set of ideas that agree with or are consistent with the facts of nature.

2. Attainment

a. Conclusion of a logical argument

b. Analysis of descriptive observations

c. Results of an experiment

3. Example: number of mayfly larvae eaten by trout in an hour

a. Logical argument

b. Descriptive observations

c. Experiment

C. Types of Reasoning

1. Induction

2. Retroduction

3. Deduction (hypothetico-deductive reasoning)

4. Arguments by authority

D. Example: winter distribution of partridges on the Palouse

1. Cold hardiness of chukar and huns

2. Is there really a difference?

a. Statistical test

b. Null hypothesis

3. Fisher (1947): "...the null hypothesis is never proved or established but is possibly disproved in the course of experimentation. Every experiment may be said to exist only in order to give the facts a chance of disproving the null hypothesis."

3. What is a fact?

E. Formal Process (Scientific Method)

1. Literature review and observations

2. Conceptual model

3. Formulating hypotheses

4. Testing hypotheses

5. Data analysis

6. Evaluation and interpretation

7. Speculation and new hypotheses

8. Publication

Recycle on from step 3 with additional hypotheses.

F. Alternate Hypotheses

1. Plat (1964) and Chamberlain (1965)

• We tend to be narrow-minded.

• We should formulate alternate hypotheses.

2. Strong inference (Plat 1964)

• Consider all reasonable alternative hypotheses and design one experiment or set of observations that would rule out many hypotheses. Then design another experiment, etc.

• see Ratti and Garton 1994:3-7.

G. Major Fallacies

1. Objectives -- What question am I asking?

2. Populations and samples -- To what population do I want to make inferences?

3. Replication

4. Controls

H. Science and Planning

1. Science and planning are intertwined

2. Decision-making

3. Science and planning compared as processes

4. Models

I. Student Responsibilities

• What is the use of the scientific method to a manager? To a researcher?

• Know the basic steps in the scientific method, be able to discuss them, and illustrate them with an example.

• What determines the usefulness of a hypothesis?

• What constitutes "proof" of a hypothesis?

• What is a fact?

• Has the scientific method a cyclic base?

• Where do insight and intuition enter into the scientific method?

• Where do the processes of induction, retroduction, and deduction occur?

• How can we obtain knowledge?

• Name four common errors in study design and illustrate each with an example.

• How are planning and scientific investigation related?

J. References

Diamond, J. R. 1986. Overview: laboratory experiments, field experiments and natural experiments. Pages 3-22 in J.R. Diamond and T.J. Case, eds. Community Ecology, Harper and Row, New York, N.Y.

Eberhardt, L. L., and J. M. Thomas. 1991. Designing environmental field studies. Ecol. Mongr. 61:53-73.

Hurlbert, S. H. 1984. Pseudoreplication and design of ecological field experiments. Ecol. Monogr. 54:187-211.

Platt, J. R. 1964. Strong inference. Science 146:347-352.

Popper, K. R. 1959. The logic of scientific discovery. Hutchinson and Co., LTD., London. 480pp. Chapter 1. A survey of fundamental problems. pp. 27-48.

Quinn, J. F., and A. E. Dunham. 1983. On hypothesis testing in ecology and evolution. Amer. Natur. 122:602-617.

Ratti, J. R., and E. O. Garton. 1994. Research and experimental design. Pages 1-23 T. A. Bookhout, ed. Research and management techniques for wildlife and habitats. Fifth ed. The Wildlife Society, Bethesda, Md.

Romesburg, H. C. 1981. Wildlife science: gaining reliable knowledge. J. Wildl. Manage. 45:293-313.

Updated 31 July 1996