Ch. 2 Key Terms.

Question 1

observation

Answer 1

is a piece of information we gather using our senses—our sight, hearing, smell, and touch.

Question 2

hypothesis

Answer 2

is a testable idea or explanation that leads to a scientific investigation. A hypothesisis more than a guess. A good hypothesis follows from what you already know and can be tested

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 be the 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

correlations

Answer 8

associations between two or more events

Question 9

Data

Answer 9

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

Question 10

Statistics

Answer 10

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

Question 11

mean

Answer 11

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

Question 12

distribution

Answer 12

is 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

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

Question 15

risk

Answer 15

is the probability of an unwanted outcome

Question 16

Models

Answer 16

are representations of objects or systems

Question 17

conceptual model

Answer 17

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

Question 18

mathematical model

Answer 18

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

Question 19

decision-

making model

Answer 19

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

Question 20

values

Answer 20

which are principles orstandards we consider important.