Scientific Method & Graphing Review

1. Problem Statement 2. Observation before Experiment/Research

3. Formulate a Hypothesis4. Experiment5. Observation6. Conclusion

Steps of the Scientific Method

1.1. Problem Statement /QuestionProblem Statement /Question: a) Uses critical thinkingb) Look at facts/Researchc) Looks for patterns

Steps of the Scientific Method

2. Research/Observation before Research/Observation before ExperimentExperiment:

BE OBJECTIVE!

a) Find out factsb) Look for patterns

Steps of the Scientific Method

3. Formulate a HypothesisFormulate a Hypothesis: “an educated guess”

a. Shows a relationship between the independent and dependent variables.

b. Testable predictionc. Explains how/why something works/occurs

Example: If soil temperatures rise, then plant growth will increase.

Steps of the Scientific Method

4. ExperimentExperiment: An organized procedure for testing a

hypothesis.Include a detailed materials list.

Step by step procedure

The procedure has TWO specified “groups”

Before we begin explaining- let’s get our brains ready.

What do these words mean?• Control group• Experimental group• Constant• Dependent variable• Independent variable

Why do you need Constants?

CONSTANTS -you must control any other variables that may

affect your results• Ex- if you are testing a fertilizer, you must keep the

temp, precipitation, acidity of soil, amount of sunlight etc. constant

Experimental group vs. Control Group

• There are two kinds of groups in an experiment– Experimental group:

• The group you are testing• Ex- the plants that receive the fertilizer

– Control group• The group that does not receive the independent

variable• ex.- the plant that do not receive the fertilizer

Control Group• Standard for comparison

– To compare the results of your variable group

• Does NOT contain the Independent VARIABLE – What you are testing

• Contains all the CONSTANTS– What you are keeping the same

• Shows that your results are related to the condition being tested.

• To make sure your results are actually because of your variable

Experimental (Test) Group

The group where you actually test the effect of your variable.

• Contains the experimental variable– Remember: Variables are things that can

CHANGE (vary) in an experiment– There are two variables in every

experiment…

Independent VariableA. The independent, or manipulated

variable, is a factor that’s intentionally varied by the experimenter.

B. Plotted on the X axis of a graphC. “Causes” your results

Dependent Variable A. Depends on (will change because

of) your independent variableB.Plot on the Y axis of a graph

C.Is your results

Example

• If plant growth and fertilizer are related, then when given fertilizer, plants will grow taller.

• What is the INDEPENDENT VARIABLE?– fertilizer

• What is the DEPENDENT VARIABLE?– Plant growth

Hypotheses relate to the variables…

The hypothesis is an educated guess about the cause and effect relationship

between the independent and dependent variables.

-The effect of the INDEPENDENT VARIABLE on the DEPENDENT VARIABLE

Steps of the Scientific Method

5. ObservationObservation:a) Results of the experimentb) Recorded as data tables, charts,

graphsc) Two kinds…

Kinds of dataKinds of data

Quantitative Data: Can be measured. Usually includes a number.

Ex: 6 feet tall, 20 cm long“Quantity”

Qualitative Data: Descriptions that can be observed but not measuredEx: purple, smelly, sharp

“Quality”

Steps of the Scientific Method

6. ConclusionConclusion: contains 3 itemsa) Include a statement that accepts or rejects

the hypothesis.b) Summary of experimental resultsc) Make recommendations for further study

and possible improvements to the procedure.

Tables and Graphs

Tables• Title• Label columns or

rows• Place unit of

measurement in top of column or row

• What’s missing on this table?

Graphs: Visual Display of Data

Do you remember where the independent and dependent variable go? Hint: Remember “IX” center

X Axis: Independent Variable

Y Axis:DependentVariable

Graph Info

• Always need a table first• Title• Label axis along with units of

measurement• Scale on axis must be of equal intervals

(you decide; are you going by 2’s, 5’s, or 10’s etc)

• One exception is the first interval

This graph does NOT start at zero, but each interval is still equal…

Types of graphs

• Bar Graph: Information collected by counting

Line Graph- Shows Trends

• The plotted points or dots represent data

• Circle uncertain values

• Use a best fit line or curve to show the average of data

Interpolate or Extrapolate?

• Interpolate- Estimating data within a set of data points

• Extrapolate- Estimating data beyond a set of data points

Circle (pie) Graph

• Shows how a quantity is broken into parts• Sometimes percentage of a whole