Aim #7: What do scientists do during experiments? Date: September 16, 2016 Aim #7: What do scientists do during experiments? HW: Packet Page 8 Quiz- Scientific Method next Wed/Thurs (day of double period) Do Now: Design a controlled experiment to test the effect of sunlight on height of a tomato plant. State the hypothesis Identify the control group Identify the dependent and independent variable Identify some factors you would keep constant

What do scientists do during experiments? They collect Data

Data Collection Data generally refers to the results of trials, or tests, completed during experiments. A data table is an important initial stage in making sense of the information you will collect while doing an experiment.

How can we organize this information? A data table makes organizing data easier to read and study

Data Tables Independent Dependent The independent variable ALWAYS is written in the LEFT column and the DEPENDENT variable in the RIGHT.

Procedure: Half the students will measure their heart rate for 1 minute during rest and write it on a piece of paper. Half the students will be instructed to complete 30 Jumping Jacks. Those students who completed the Jumping Jacks will measure their heart rate for one minute and write it on a piece of paper.

Our Results: Group A Group B Students at rest HR 1 2 3 Students after 30 JJ HR 1 2 3 AVG= AVG=

Let’s Graph!!!

Why do scientists utilize graphs? A carefully constructed graph can provide us with a large amount of information quickly. It also allows us to carefully analyze our results from an experiment.

Types of Graphs: Line Graph What is this graph telling us?

Types of Graphs: Pie Graph What is this graph telling us?

Types of Graphs: Bar Graph Histogram What is each graph telling us?

Date: September 19, 2016 Aim #7: What do scientists do during experiments? HW: Graphing Practice Quiz- Scientific Method next Wed/Thurs (day of double period) Do Now: Design a controlled experiment to test the effect of sunlight on height of a tomato plant. Set up an appropriate data table

Reviewing Homework Practice Regents Questions

Base your answer to the following question on the information below and on your knowledge of biology. You are the head of the research division of the Leafy Lettuce Company. Your company is experimenting with growing lettuce using hydroponic technology. Hydroponic technology involves growing plants in containers of growth solution in a greenhouse. No soil is used. The growth solution that the company uses contains water, nitrogen, and phosphorus. The company wants to know if adding iron to this formula will improve lettuce growth.   Briefly describe how to test the effect of the formula with iron added. In your description be sure to: State a hypothesis to be tested in the new experiment. State how the control group will be treated differently from the experimental group. Identify two factors that must be kept the same in both the experimental and control groups. State what type of data should be collected to support or refute the hypothesis.

A television advertisement claims that a certain brand of cough drop reduces coughing for 8 hours. Describe an investigation that could be used to determine if this claim is valid. In your answer, include a description of: The treatment to be given to the experimental group. The treatment to be given to the control group. The data to be collected When the data should be collected One observation that would lead to the conclusion that the claim is valid.

Many people who are in favor of alternative medicine claim that large doses of vitamin C introduced into a vein speed up the healing of surgical wounds. Describe an experiment to test this hypothesis. Your answer must include at least: The difference between the experimental group of subjects and the control group. Two conditions that must be kept constant in both groups. Data that should be collected An example of experimental results that would support the hypothesis.

Let’s Graph the Results from our Experiment: We will be making a line graph from our results. We will graph the average heart rate for the control group and the experimental group.

Rules for Constructing Graphs: Rule 1: The dependent variable is plotted on the vertical, Y-Axis. Rule 2: The Independent Variable is plotted on the horizontal, X-Axis. Rule 3: The spacing between the numbers on both axes must be in equal increments.

Our Graph: The Effects of Exercise on Heart Rate Y Dependent Variable Independent Variable Dependent Variable 120 Average Heart Rate (Beats per minute) 80 40 10 20 30 40 Number of Jumping Jacks

What are our results? Our results indicate that heart rate increased after the students performed 30 jumping jacks.

What is our conclusion? Was the hypothesis supported or rejected? This experiment supported our hypothesis. Physical exercise (Jumping Jacks) increases a person’s heart rate.

Let’s Practice Graphing

Technique for Constructing a Line Graph 1. Identify the variables to be plotted Independent variable the variable manipulated by the experimenter is plotted on the x-axis (horizontal axis) Dependent variable the factor responding to changes in the independent variable plotted on the y-axis (vertical axis) 2. Determine the scale of the axes Determine each axis individually May easily be determined by taking the largest value to be plotted and dividing by the number of blocks and then rounding up to the nearest convenient number The graph should be spread to occupy the most available space. 3. Number and label each axis indicating the appropriate units. 4. Plot each data value on the graph with a point. 5. Draw a line that best fits the data points. Do not connect data points to the origin unless there is data to support this Only connect the points if the directions tell you to do so. 6. Provide a title which clearly indicates what the graph is about. If the graph has more than one set of data, provide a key to indicate what is represented by the different lines.