BASIC SITUATIONAL ANALYSIS

For Science Scenarios

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John Schmied©2014

WHAT DO YOU DO IN A SITUATIONAL ANALYSIS? You are given a scenario (short story) & you analyze the situation. By analyzing you:

Identify key parts of the experiment Study subject (ss) Manipulated (MV), Responding (RV), Controlled (CV) & Uncontrolled variables (UCV) Control (CT) & Experimental trials (ET)

Then you use these key items to create a question , a prediction, and a hypothesis (QPH)

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THE KEY PARTS OF A SCIENTIFIC SITUATIONAL ANALYSIS

Study Subject (SS) Manipulated (changed) Variable (MV) Responding (measured) Variable (RV) Controlled Variables (CV) (Not MV or RV!) Uncontrolled Variables that Matter (UCV) (Not MV or RV!) Experimental Trial (ET) Control Trial (CT) You’ll create:

Scientific Question (contains SS, MV, RV)Prediction (If – Then, compared to statement)Hypothesis (If, Then, compared to, Because [MV,RV, SS &

Reason Why] statement)

BASIC DEFINITION REVIEWStudy Subject (SS) = The subject (animal, plant, object etc) that is being studied.

Manipulated (changed) Variable (MV) = The ONE variable being changed for the purpose of testing the hypothesis. There’s only one MV

Responding (measured) Variable (RV) = The variable being measured. Usually changes in response to changes in the manipulated variable. There can be more than one RV.

Controlled Variables (Not MV or RV) = A variable kept the same in an experiment

Uncontrolled Variables [that Matter] (Not MV or RV) = Variables that are not controlled & can affect the results of an experiment (cause error)

Control Trial = The “natural” situation, used to compare to the Experimental Trial. (Does not have the MV)

Experiment Trial = Trial contains the manipulated variable, used to test the hypothesis.

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There’s only one MVin an

experiment!

There can bemore than one RV in anexperiment

In this experiment 5 Arabian horses are fed a mix of all kinds of grass.

Another group of 5 Arabian horses are

only fed oats

The Horse Race

A month later, these groups are

raced against each other

in a mile race. Elapsed times

are recorded &compared.

Other data:• The entire track surface is dry

& smooth• All horses have the same type

of saddles• Jockeys weigh between 120-

135lbs

Tell the:a. SS b. MV c. RVd. CT e. ETf. Controlled Variablesg. Uncontrolled Variable(s)

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5 Arabian horses fed a mix of all kinds of grass.

5 Arabian horsesonly fed oats

The Horse Race

Tell the:a. SS = Arabian Horses b. MV = Diet of the horsesc. RV = Total Elapsed times of each groupd. CT = Arabians - all kinds of grass e. ET = Arabians - Oatsf. Controlled Variables = Same: saddle, distance, track surface, type & number or horses, same trackg. Uncontrolled Variable(s) = Jockey’s weight

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The Horse RaceWriting A Scientific Question

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1. Write Questions, Predictions & Hypothesis about the Experimental Trial. 2. Do not create scientific questions that can be answered by a simple “Yes” or “No”.3. Do not use the word CHANGE. Be SPECIFIC ( Instead use terms like Increase, Decrease, Remain the same)4. Use proper names (nouns). Don’t use pronouns.5. Use correct conventions. (Capitalization, question marks, etc.)

Basic rules for writing scientific questions.

The Horse Race

Data Needed for QPH:a. SS = Arabian Horses b. MV = Diet of the horsesc. RV = Total Elapsed times of each groupd. CT = Arabians - all kinds of grass e. ET = Arabians - Oats

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How will feeding oats to

Arabian horses affect

the horse’s time in the mile?

SS

MV

RV

The Horse Race

If contains the Manipulated Variable and Study Subject (in either order!),

Then contains the Experimental Trial, then a specific prediction about the Responding Variable

Compared to contains the Control (if a control is used)

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Prediction

If – Then – Compared to Format

The Horse Race

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IF Arabian horses are fed a diet of oats,

Then the horses fed oats will run faster,

Compared to Arabian horses fed grass.

SS MV

Prediction about RVET

CT

Prediction “If, Then, Compared to”

Because oats have more nutrition than grass.

Therefore the Arabian horses will run a faster time

in the mile on a diet of oats.

The Horse Race - BECAUSE

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RVSS

MV

Reason Why

Hypothesis “Because…. Therefore”

Hypothesis” Add Because – Therefore statement.

a. The Because gives a logical, realistic, reason for

choosing the predicted outcome.

b. The Because includes the Reason Why as well as

the Study Subject, Manipulated Variable, &

Responding Variable in the explanation.

Because oats have more nutrition than grass.

Therefore the Arabian horses will run a faster time

in the mile on a diet of oats.

The Horse Race

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RVSS

MV

Reason Why

Completed Hypothesis

IF Arabian horses are fed a diet of oats,

Then the horses fed oats will run faster,

Compared to Arabian horses fed grass.

SS MV

Prediction about RVET

CT

In this experiment 12 Holstein cows are kept in

pasture all day.

Another group of 12 Holstein cows are given exercise in the morning, then kept in pasture.

Holstein Milk Challenge

At 6 AM & 5 PM the 2 groups are

milked in the barn. The total amount of milk given by each

group is recorded & compared. Other data:

• The cow pasture is 40 acres• During the trials two of the

pasture cows get pregnant. • All cows are given the same feed and milked w/same machines• One of the exercise cows escapes,

but is found the next morning

Tell the:a. SS b. MV c. RVd. CT e. ETf. Controlled Variablesg. Uncontrolled Variable(s)

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In this experiment 12 Holstein cows are kept

in pasture all day.

Another group of 12 Holstein cows are

exercised in the morning, then kept in pasture.

Holstein Milk Challenge

a. SS = Holstein Cows b. MV = Exercise c. RV = amount of milk given by each group’s cowsd. CT = Cows in pasture e. ET = Cows given exercisef. CV = Same: Pasture, feed, time milked, barn, machines g. UCV = 2 “pasture” cows get pregnant, 1 “exercise” cow escaped over night

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Use your knowledge

to create a: Question

Prediction and a

Hypothesis for this challenge

Holstein Milk Challenge

Whoa Bessie !!!