Ch. 2 Key Terms.

Question 1

Observation

Answer 1

An observation is a piece of infor-mation we gather using our senses—our sight, hearing, smell, and touch.

Question 2

Hypothosis

Answer 2

A hypothesis (hie PAHTH uh sis) is a testableidea or explanation that leads to a scientific investigation.

Question 3

Prediction

Answer 3

a logical statement about what will happen if the hypothesisis supported

Question 4

Experiment

Answer 4

is a procedure designed to test a hypothesis under controlled conditions.

Question 5

Variable

Answer 5

is the factor of interest, which, in our example, would bethe level of phosphate in the water.

Question 6

Experimental Group

Answer 6

The group that receives the experimental treatment

Question 7

Control Group

Answer 7

The group that does not receive the experimental treatment

Question 8

Data

Answer 8

The information that a scientist gathers during an experiment, which is often in numeric form

Question 9

Correlation

Answer 9

associations between two or more events

Question 10

Statistics

Answer 10

the collection and classification of data that are in the form of numbers

Question 11

Mean

Answer 11

the number obtained by adding the data fora characteristic and dividing this sum by the number of individuals.

Question 12

Distribution

Answer 12

the relative arrangement of the members of a statistical population

Question 13

Probability

Answer 13

The chance that something will happen

Question 14

Sample

Answer 14

a group of individuals or events selected to represent the population.

Question 15

Risk

Answer 15

the probability of an unwanted outcome

Question 16

Model

Answer 16

representations of objects or systems

Question 17

Conceptual Model

Answer 17

a verbal or graphical explanation of how a system works or is organized

Question 18

Mathematical Model

Answer 18

one or more equations that represents the way a system or process works.

Question 19

Value

Answer 19

are principles or standards we consider important

Question 20

Decision-making Model

Answer 20

is a conceptual model that provides a systematic process for making decisions.