Scientific Method & Graphing Review

1.Problem Statement 2.Observation before Experiment/Research 3.Formulate a Hypothesis 4.Experiment 5.Observation 6.Conclusion

Steps of the Scientific Method 1.Problem Statement /Question 1.Problem Statement /Question: a)Uses critical thinking b)Look at facts/Research c)Looks for patterns

Steps of the Scientific Method Research/Observation before Experiment 2. Research/Observation before Experiment: BE OBJECTIVE! a)Find out facts b)Look for patterns

Steps of the Scientific Method Formulate a Hypothesis 3. Formulate a Hypothesis: “an educated guess” a.Shows a relationship between the independent and dependent variables. b.Testable prediction c.Explains how/why something works/occurs Example: If soil temperatures rise, then plant growth will increase.

Steps of the Scientific Method Experiment 4. Experiment: 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 Variable A.The independent, or manipulated variable, is a factor that’s intentionally varied by the experimenter. B.Plotted on the X axis of a graph C.“Causes” your results

Dependent Variable A. Depends on (will change because of) your independent variable B.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 Observation 5. Observation: a)Results of the experiment b)Recorded as data tables, charts, graphs c)Two kinds…

Kinds 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 measured Ex: purple, smelly, sharp “Quality”

Steps of the Scientific Method Conclusion 6. Conclusion: contains 3 items a)Include a statement that accepts or rejects the hypothesis. b)Summary of experimental results c)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: Dependent Variable

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