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Scientific Method Vocabulary. Observations. Any information collected with the senses. The skill of describing scientific events. Inference. Conclusions or deductions based on observations . The process of drawing a conclusion from given evidence.
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Observations • Any information collected with the senses. • The skill of describing scientific events.
Inference • Conclusions or deductions based on observations . • The process of drawing a conclusion from given evidence.
Tracks like these are common in parts of New England and in the southwestern United States. What do you OBSERVE? What can you INFER?
Data recorded as an observation Example – the substance has a sweet taste Describe a Feature/looks Qualitative data
Data that is recorded in numbers. Example – 3 inches tall Think numbers Or amounts Quantitative data
Independent Variable (also called the Manipulated Variable) • What you are testing in an experiment • The cause • Purposely changed • I change this
What you are measuring in an experiment The Data The Effect Dependent Variable (also called the responding variable)
Variable Mapping Dependent variable Plant Growth sunlight • Independent Variable • Test 1 at a time • Soil • sunlight- • Water • potsize water Plant Growth Constants: stay the same except for one being tested Sunlight Pot size Water soil soil This Photo by Unknown Author is licensed under CC BY-NC-ND Pot size
Practice • You want see if plants grow better when they are exposed to classical music. You take 4 identical plants, potted in the same containers, under the same conditions. The only difference is that 2 plants will be exposed to classical music as they grow. The others will grow exposed to no music. After 2 weeks you compare the growth rates. • Independent Variable :_________________ • Dependent Variable: ___________________ • Constants: __________________
Variable practiceIdentify the IV, DV, and Constants • Fertilizer in soil increases flower production • Medicine A will reduce the incidence of headaches • If zinc tablets are taken, then the number of colds per year is reduced • If water is present, then the number of bacteria in garbage bins increases • Girls throw softballs further than boys
Materials in an experiment that are the same in both the control group and the experimental group This never changes If it did that would make 2 independent variables = NOT GOOD Constant
Control Group • Used for comparison • No treatment • Unchanged throughout experiment
Title • Should be asked or stated at the beginning of every experiment. • Should be answered in your conclusion not at the beginning. • The effect of _________ on __________. • Example: What is the effect of weight on a paper airplane?
Procedure • Your Procedure must be • In a step by step format • Detailed • Reproducible Written like a recipe!!
Tables and Graphs • Every lab should have your data represented in a table and a graph – THEY ARE NOT THE SAME!!
D – Dependent R – Respondent Y – Y axis M – Manipulated I – Independent X – X axis DRY MIX
TAILS • Every Graph Should have • T – Title • A – Axis Labels • I – Intervals • L – Labels • S - Scale
What kind of graph should I use? • Line graph – change over time • Bar graph – comparison • Scatter plot – shows trends • Pie chart or circle graph – shows % • Picture Graph – uses words or pictures to represent data
Hypothesis(plural – hypotheses) • Special kind of prediction How to write a hypothesis • Use an If, Then statement • IF the independent variable changes, THEN the dependent variable changes, because. • This type of sentence shows what the IV will do to the DV
Materials • 3 Hershey’s Kisses and a stop watch
Procedure • Place one of the kisses in your mouth. DO NOT chew, and DO NOT move your tongue around. • Record the time it takes for this candy piece to dissolve. • Place a second kiss in your mouth. DO move it around in your mouth but DO NOT chew. • Repeat step 2 • Place a 3rd kiss in your mouth. This time move it around in your mouth as you chew. • Repeat step 2
Let’s Start our Short Report…. • Make a title… (The effect of …. On ….) • Write a hypothesis (If….then…because...) • Complete the Experimental Design Summary. • IV (Levels and Trials) • DV • 4 Constants • Control
Title • The effect of chewing the on the rate chocolate melts.
What type of data/observations would be collected with this experiment? Make your observations. Why did you get the results you did? Now what do you do?
Science Skills: Variables Self Check Click to test yourself
A variable is something that can vary or change. What are the variables in this statement? The time it takes to run a 10 km race depends on the amount of training the runner does. Click to check your answers
What are the variables in this statement? The temperature of water is measured at different depths in a lake. Click to check your answers
What are the variables in this statement? The more water a plant gets, the taller it will grow. Click to check your answers
What are the variables in this statement? The number of puppies in a litter is determined by the weight of the mother dog. Click to check your answers
What are the variables in this statement? The Texas A & M Extension Service has been counting the number of coyotes in Bexar County. Will the number of coyotes have any effect on the rabbit population? Click to check your answers
The time it takes to run a 10 km race depends on the amount of training the runner does. The independent variable is the amount of exercise. The dependent variable is the time it takes to run a 10 km race. It is not enough to say just “time” or “training” – you must describe the I.V. and tell how the D.V. is measured. Click for another question
The temperature of water is measured at different depths in a lake. The independent variable is the depth of the lake. The dependent variable is the temperature of the water. Click for another question
The more water a plant gets, the taller it will grow. The independent variable is the amount of water. The dependent variable is the height of the grass. Click for another question
The number of puppies in a litter is determined by the weight of the mother dog. The independent variable is the weight of the mother dog. The dependent variable is the number of puppies in the litter. Click for another question
The Texas A & M Extension Service has been counting the number of coyotes in Bexar County. Will the number of coyotes have any effect on the rabbit population? The independent variable is the number of coyotes. The dependent variable is the rabbit population.
Cohesion The force between particles in a substance that works to hold it together Surface Tension Water molecules have bonds that hold them together. At the surface of the water, the molecules hold on to each other even more tightly because there are no molecules pulling on them from the air above. As the molecules on the surface stick together, they form an invisible "skin" called surface tension. Help with the Penny Lab
Results Summary • Summarize your data in one sentence. • Shows Trends. • Example… • The bigger the coin the more drops of water the coin would hold.
Conclusion – Answer these questions in a paragraph… • What was the purpose of the experiment? • What were the major findings? • Was the hypothesis supported by the data? • How did your findings compare to your classmates? • What happened that you did not expect? Why do you think this happened? • How would you improve this experiment next time? • What recommendations do you have for further study?
Descriptive Based on observations Examples Dissection Making Models Observing Wild Animals Experimental The manipulation and control of variables 2 kinds of Research
Testing Meds. Vocab • Trial – a try – should have as many as possible in an experiment • Sample Size – the number of people or subjects in an experiment • Placebo – a “fake medicine” used as a control – contains no drugs – usually made of sugar • Trade-off - Giving up one thing in favor of another
Clinical trials must have… • 1 – Consent or permission from the subject • 2 – Compensation or payment for time • 3 – the subject must be informed of all risks involved