Science 9 Summer Assignment book pages

observation

using our senses to study the world

Empirical evidence

gathered through observation; logical reasoning and testing

data

evidence that can be analyzed

Qualitative data

descriptions of a phenomenon that can include sights, sounds, and smells; often used to report what happens but not how it happens

Quantitative data

characteristics that can be measured or counted, such as mass, volume, and temperature; anything that is expressed as a number that can be used to explore how something happens

hypothesis

a proposed answer for a scientific question; must be specific and testable

nonsignificant results

the data show no effect, or an effect so small that the results could have happened by chance

statistically significant

The data show an effect that is likely not due to chance. When data do not support a hypothesis, the hypothesis is rejected. But these data are still useful because they often lead to new hypotheses.

experiments

scientists study factors called independent variables and dependent variables to find cause-and-effect relationships

independent variable

a condition that is manipulated, or changed, by a scientist

dependent variables

observed and measured during an experiment; they are the experimental data

constants

the conditions that do not change during an experiment

theory

a proposed explanation for a wide range of observations and experimental results that is supported by a wide range of evidence; not easily accepted in science and by definition are never proved

scientific law

defines relationships that are valid everywhere in the universe; describes without providing any explanation

scientific journals

primary sources of scientific information and include results and conclusions

secondary sources

almost all scientific knowledge presented to the public comes from

control group

exactly the same as the experimental group--except for the factor that is being tested

experimental group

testing whether the independent variable has an effect

operational definition

description of the exact way in which you will measure the dependent variable

written procedure

step-by-step guide on how to complete the experiment

organize and analyze the data

in order to draw conclusions from the data you need to

data table

used to organize and record data that are collected; can help identify trends in data

line graph

used to show a relationship between two variables; particularly useful for showing changes in the variables over time

negative correlation

if an increase in the value of one variable is associated with a decrease in the value of the other variable

positive correlation

if an increase in one variable is associated with an increase in the other variable

no correlation

if there is no relationship between the two variables

bar graph

a type of graph in which the lengths of the bars are used to represent and compare data

discrete data

can have only whole-number values

combination graphs

show two sets of data on the same graph; one set of data may be shown as a line graph and the other as a bar graph

histogram

a type of bar graph used to show the frequency distribution of data

frequency distribution

displays the number of cases that fit into each category of a variable

scatterplot

a type of graph used to identify a trend or correlation between two variables; data is plotted but not joined together

circle graph (pie chart)

a type of graph used to represent parts of a whole