Scientific Method Observation Gather Information Hypothesis Experiment Conclusion
What is an Observation? Definition: Using senses to gather information Observations lead to questions “what is the effect of …on …?”
Two types of Observations 1. Qualitative: Using your senses to describe something Ex: Mrs. Peddie has Brown Hair 2. Quantitative: Using tools to take a numerical measurement Ex: Mrs. Peddie is 5 ft 2 in.
Hypothesis Predicts the answer to a question Hypotheses are based on--- Past Experience Observations Research
The format for writing a hypothesis “IF . . . THEN . . .because….” Example : IF I exercise, THEN my heart rate will increase BECAUSE heart rate is dependent upon activity levels.
What is an Experiment Experiments test your Hypothesis The experiment tests ONE VARIABLE (factor that changes) EX:= increasing or decreasing your Exercise level Experiments need a CONTROL GROUP (to compare results to) EX: = your heart rate at rest. Constants: the parts of the lab that must remain the same EX: = temperature, type of exercise, time
Types of Variables Dependent Variable: Is the data collected through observation and measurement heart rate Independent Variable: Variable that is manipulated (changed) during the experiment. rest, stand, walk, run
Conclusion Did the experiment support the hypothesis? Analysis …Paragraph explaining your results and discussing these questions. If you did the experiment again, what would you do differently? What did you learn? Possible Errors
Theory Theory = hypothesis supported by many experiments over time Examples of theories: Gravity or Evolution
Identify the Axes Y- Axis X- Axis
Identify the Axes Y- Axis Dependent Variable (what is observed and measured) X- Axis Independent Variable (what is changed by the scientist)
One way to remember which data goes on which axis is the acronym DRY MIX. D.R.Y.M.I.X. D- Dependent M-Manipulated R- Responding I- Independent Y- Y-axis X- X-axis DRY MIX
Write an appropriate title for the graph at the top. The title should contain both the independent and dependent variables. Title
Decide on an appropriate scale for each axis. The scale refers to the min and max numbers used on each axis. They may or may not begin at zero. The min and max numbers used for the scale should be a little lower than the lowest value and a little higher than the highest value. This allows you to have a smaller range which emphasizes the comparisons/trends in the data. Scale
Scale The Y-axis scale is from 0-100. The largest value though is only 35.
Scale • The Y-axis scale is now from 0-40. • This does a better job emphasizing the comparisons between coins.
Look at your minimum and maximum values you set up for both the Y and X-axis. (For most bar graphs, the X-axis will not have numerical values.) Decide on an appropriate interval for the scale you have chosen. The interval is the amount between one value and the next. It is highly recommended to use a common number for an interval such as 2, 5, 10, 25, 100, etc. Intervals
Intervals The interval for the Y-axis is 20. The X-axis does not have numerical data and does not need an interval.
Both axes need to be labeled so the reader knows exactly what the independent and dependent variables are. The dependent variable must be specific and include the units used to measure the data (such as “number of drops”). Labels
Labels DV label IV label
Another handy acronym to help you remember everything you need to create your graphs….. T.A.I.L.S. Title Axis Interval Labels Scale TAILS
TAILS Title: Includes both variables Axis: IV on X-axis and DV on Y-axis Interval: The interval (4) is appropriate for this scale. Label: Both axes are labeled. (UNIT) Scale: Min and max values are appropriate.
Bar Graphs • Bar graphs are descriptive. • They compare groups of data such as amounts and categories. • They help us make generalizations and see differences in the data.
Line Graphs • Line graphs show a relationship between the two variables. They show how/if the IV affects the DV. • Many times, the IV plotted on the X-axis is time. • They are useful for showing trends in data and for making predictions. • Can be used to compare multiple sets of data, using different lines within the same graph
Planting Procedure • Label the RIM of Styrofoam cups • Group# and Period, Date • control or experimental • Amount of Water • Punch 3 holes in bottom of cup (already done) • Place one beaker of soil in cup (60 ml) • Plant sprinkle ¼ teaspoon of grass seeds evenly across the soil • Place another beaker of soil (60 ml) over seeds • Water (50ml/one beaker) • More water is needed at planting to get the seeds to germinate
Data Collection • Water daily (before school on off days) • Place watered amount and date on cups • Measure on days that you have biology • Place measurements and date on cup and in your data table
Six Criteria of Science : Consistent, Observable, Natural,Predictable, Testable, Tentative.
Consistency : The results of observations and/or experiments are reasonably the same when repeated. Green plants will grow towards a light source. Walking under a ladder will cause bad luck.
Observability :The event or evidence of the event, can be observed and explained. The observations are limited to the basic human senses or to extensions of the senses. Some plants eat meat. Extraterrestrial beings have visited Earth.
Natural : A natural cause (mechanism) must be used to explain why or how the event happens. 1. Green plants convert sunlight into energy. 2. With a rod, Moses parted the sea so his people could cross to the other side..
Predictability : Specific predictions can be used to foretell an event. Each prediction can be tested to determine if the prediction is true or false. Without sunlight (or artificial light), green plants will die. If you are a "Scorpio", your horoscope for today is "You'll be saying 'I feel rich !' Lunar position highlights back pay, refunds, correction of accounting error."
Testability : the event must be testable through the processes of science, and controlled experimentation. The Bermuda Triangle causes ships and planes to sink and disappear. Life comes from life and cannot come from non-life.
Tentativeness : Scientific theories are changeable and correctable, even to the point of the theory being proven wrong. Scientific theories have been modified and will continue to be modified Pluto was once a planet but due to it’s orbits, is now considered a dwarf planet. We know that the world began about 6000 years ago, and nothing will change that.
What Factors effect Seed Germination? Experimental Design Activity
The Scientists Jean Baptist Lamarck vs. Charles Darwin
Jean Baptiste LamarckEvolution occurs as structures develop through use, or disappear because of disuse, and these “acquired characteristics” are passed to offspring EXAMPLE: Over a Giraffes Lifetime it can stretch it’s neck and it’s offspring will be born with long necks…. Valid?
Darwin and The Monkey! THIS IS NOT WHAT HIS THEORY SAYS
Who was Charles Darwin Studied Medicine Hated the sight of blood Received a BA in Theology Had 10 children Darwin was a Naturalist on the HMS Beagle
Theory of Evolution In The Galapagos Islands, Darwin collected species of finches (13) Each had a specialized diet and beak structure These finches all closely resembled a South American finch ancestral species On the trip Darwin saw things he could only attribute to a process called “Natural Selection”