SOLVE PROBLEMS OR ANSWER QUESTIONS Scientific Investigations

Scientific Method Process that provides a logical approach to problem solving. Science: Understanding our natural world.

Step 1: Identify a Testable Question (or Problem) Example:“Does fertilizer make roses grow taller?” Do NOT use questions about opinions, emotions, or supernatural events.

Step 2: Research the Topic Make observations. Gain information from trustworthy sources. Examples: Experts, scientific journals, and textbooks. Use the internet with CAUTION!

Step 3: Form a Hypothesis A clear and testable statement about the natural world. Possible explanation, inference, or prediction. Does NOT have to be correct. Based on observations and other information gathered from research.

The hypothesis is written as a statement. NOT Good: “Why do some objects fall faster than others?” Good: “Objects fall at different speeds due to their shapes”.

The hypothesis should be clear. NOT Good: “Sometimes there is morning dew on the grass”. Good: “When the temperature drops below 50°F at night, the grass will have dew in the morning”.

The hypothesis should be testable. Must be possible to conduct a scientific investigation to support or disprove the hypothesis. NOT Good: “Dogs are happier than cats”.

Step 4: Design an Experiment (Investigation) to Test the Hypothesis Variables: Factors that can change. Fair Test: Only ONE variable is changed. Types of variables:  1. Changed (independent variable)  2. Carefully Controlled (constants)  3. Observed or Measured (dependent variable)

Step 5: Collect and Interpret Relevant Data Observations and Measurements Use scientific notebook. Use tables and graphs to analyze.

Step 6: Explain and Compare the Results Conclusions should be made about what happened. Do the results support the hypothesis, or not? Communicating results helps people learn.

Types of Scientific Investigations Seek out, explain, and predict natural phenomena. Observational: Purpose is to generate hypotheses. Experimental: Purpose is to test hypotheses (controlled).

Choosing the Type of Investigation Field study: observes organisms or events in nature. Performing a controlled scientific experiment Making models: computer simulation programs Review existing work – check other investigations

Reviewing Vocabulary for Science Experiments Control: Part of an experiment not being tested. Control Group: Used to compare with the results. Procedure: Describes the steps of an experiment. Error: When scientists make a mistake. (Oops!) Conclusion: Summarizes the experiment results.

Models Make ideas and items easier to understand. Show what something looks like (Ex. Drawings). Show how something functions (Ex. Systems). Help analyze and predict what will happen.

Types of Models 3-Dimensional models can test stability of designs. Maps show directions and distances (roads, rivers). Watershed Maps show the terrain of the area (hills). Globes show the whole Earth without distorting. Concept Maps shows relationships between ideas.

Models Models use Familiar Objects (Earth analogy) Models have Limitations (small, different materials)

Lab Tools Used to make measurements and gather data. Scientific Notebook or Journal (words, pictures) Ruler, Meter Stick, and Tape Measure (length) Triple Beam Balance (mass)

Electronic Balance (mass) Spring Scale (weight, or gravitational force) Graduated Cylinder (volume of liquids) Test Tube (used to store and heat liquids)

Beaker (Used to store and heat liquids, volume) Petri Dish (Use to grow cultures of microorganisms) Thermometer (temperature) Temperature & pH Probes (connects electronically) pH meter measures how acidic or alkaline

Hot Plate (heat substances such as liquids) Microscope and Stereoscope (used too view objects) Hand Lens (used to view objects up close) Forceps (used to grasp and hold objects)

Magnet (used to separate mixtures or test properties) Stopwatch (Timer) (used to measure time) Calculator (used to solve math problems) Computer (used to look up information)