1. Evaluating and Interpreting Information
Chapter 10
Evaluating and
Interpreting Information
Technical Communication, 11th Edition
John M. Lannon

2. Questions to Ask When Evaluating Sources
Is the source up-to-date?
How current is the information?
Is the printed source dependable?
What is the sources reputation?
Is the electronic source trustworthy?
Can the source be trusted?
Is the information relatively unbiased?
Who sponsored the study and why?
How does this source measure up to others?
What are similar sources saying?

3. Evaluate the Evidence Is the evidence sufficient?
Do you need more information to reach a conclusion?
Is this hard evidence or soft evidence?
Can it be verified? Is it opinion or speculation?
Is the presentation of evidence balanced and reasonable?
Is there any overstatement, omission of vital facts, or deceptive framing of the facts?
How are the facts being framed?
Does it attempt to obscure the real issue? Relay facts in a more positive light?

4. Interpret Your Findings
What level of certainty is warranted?
Do you need the ultimate truth, a probable answer, or would an inconclusive answer suffice?
Are the underlying assumptions sound?
E.g. IQ test scores predict academic performance.
Assumptions: Students don’t know their scores, and all students receive the same curriculum.
To what extent has personal bias influenced the interpretation?
Are other interpretations possible?

5. Avoid Errors in Reasoning
Identify and evaluate all possible causes and rule out unlikely ones
Select the most probable causes and evaluate them
Identify the definite or
immediate causes

6. Avoid Errors in Reasoning
Faulty Generalizations
E.g. Female brains are smaller than male brains; therefore, women are the less intelligent gender.
Faulty Causal Reasoning
Why does our university not have daycare facilities? Lack of need, lack of interest, lack of space

7. Avoid Statistical Fallacies
Give examples of each of the following type of erroneous or misleading statistic:
The sanitized statistic
The meaningless statistic
The undefined average
The distorted percentage figure
The bogus ranking

8. Acknowledge the Limits of Research
Obstacles to validity and reliability
Valid – correct findings
Reliability – findings that can be replicated
Flaws in study design
Sources of measurement error
Sources of deception

9. See the checklist on interpreting research findings and chapter 10, page 194.

10. Interpretation Errors Exercise
What’s wrong with these statements of findings?
The overall cancer rate today is higher than in 1910.
One out of every five patients admitted to Central Hospital dies?
In a recent survey, rates of emotional depression differed widely among different countries – far lower in Asia than in Western countries.
Teachers are mostly to blame for low test scores and poor discipline in public schools.

11. Faulty Assumptions Bottled water is safer than tap water.
Forest fires should always be prevented or suppressed immediately.
The fewer germs in the environment, the healthier the children.
The more soy we eat, the better.