Ex: Which vegetables grow better in my garden Ex: Which vegetables grow better in my garden? Not testable – can’t measure “better” Will carrots be the first in my vegetable garden ready to harvest? Testable – answered by investigation and measureable

Testable vs. Not Testable Questions Why does weathering happen on Earth? Not Testable – something you can look up or research Does water have a density higher than 2? Not Testable – yes or no question answered through research How do different bridge structures stand up in earthquakes? Testable – You can improve the question by being specific about the types of bridge structures you want to test How do I measure distance? Not Testable – asking to perform a skill

Form a Formalized Hypothesis IMPORTANT: A scientific investigation shows the effects of a single IV on a DV

Variable: A quantity that can have more than a single value Testing Hypothesis…. Variable: A quantity that can have more than a single value Constant – a factor that does not change when other variables change

Controlled Experiment Experiment in which only one variable, the manipulated variable, is deliberately changed at a time. All other variables remain constant, or controlled. Control –a standard to which test results can be compared Control Group - all the factors that are kept the same Experimental Group- same as the control group, except for one factor being tested REPEAT, REPEAT, REPEAT

Within the experimental group are two types of variables a) Independent (manipulated): the variable that is changed in a scientific experiment to test the effects on the dependent variable. “scientists control” b) Dependent (responding) the variable being tested in a scientific experiment. “scientist observe/measure the results” Part of experiment affected by independent. Note: variables that do not change are constant

Conduct experiment and collect data Conduct experiment and collect data. Data: Information gathered Qualitative Data Overview Deals with descriptions. Data can be observed but not measured. Colors, textures, smells, tastes, appearance,etc. Qualitative → Quality

Quantitative Data Overview: Deals with numbers. Data which can be measured. Length, height, area, volume, weight, speed, time, temperature, humidity, sound levels, cost, members, ages, etc. Quantitative → Quantity

Example : Latte Quantitative data: 12 ounces of latte serving temperature 150º F. serving cup 7 inches in height cost $4.95 Qualitative data: robust aroma frothy appearance strong taste burgundy cup

Identifying parts of the experiment Ex 1: You want to see if a fertilizer can cause plants to grow taller in height.

DV:(observed, measured or tested): height of plant IV: (what is changed to see how it affects plant growth): fertilizer constants (variables not changed): amt of sunlight, amt of water, room temp, type of soil, type of plant

control group: plant that is NOT fertilized; constants same as for tested plant predict what might happen in experiment: Small amounts of fertilizer will result in a larger plant.

What is a FORMALIZED hypothesis: “If, ….Then….” statement with a tentative relationship and prediction. If amount of plant growth is related to fertilizer, then exposing plants to small amounts of fertilizer will result in more plant growth.

IF dependent variable IS RELATED TO independent variable THEN the changes in the independent variable WILL RESULT IN changes in the dependent variable .

How to write a Hypothesis What is NOT a good hypothesis: Ex: “Plants will grow taller when fertilized.” This is a prediction. Ex: “Fertilizer causes plants to grow bigger” This is a possible conclusion. Ex: “Plants may grow bigger when fertilized.” Could be hypothesis because it uses may. But not tell us how we support it. Ex: “If I fertilize the plants, then they will grow bigger” This is a prediction without a relationship to support

Ex 2: You want to see if cheese develops mold quicker in a warmer temperature.

DV: amount of mold (or quicker growth) on cheese IV: temperature constants (variables not changed): amt of cheese, type of cheese, cheese brand, moisture, surface cheese is placed

control group: cheese left in refrigerator; constants same as for tested mold prediction: warmer temperatures will result in more growth of mold (or quicker growth) on cheese

Write a formalized hypothesis for the mold example. If amount of mold on cheese is related to temperature, then exposing cheese to warmer temperatures will result in more growth (or quicker growth) of mold on cheese.

IF dependent variable IS RELATED TO independent variable THEN the changes in the independent variable WILL RESULT IN changes in the dependent variable .