The Scientific Method Scientists make careful observations of the world around them. They ask questions & form hypotheses. They test their hypotheses, collect, & analyze their data.

Making Observations & Collecting Data

Let’s test your observation skills. Take a good look at this picture:

Are there cars parked on the side of the road? What color is the pickup truck driving in the road? Are there any minivans around? What does the blue sign say? What’s the speed limit? Are there pedestrians on the road?

How many did you get correct? Yes Blue Yard Sale 35 mph No

Making Observations & Collecting Data During labs, use your observations to collect data Your observations can be qualitative or quantitative. The petals are pink. The flower has 5 petals.

Making Observations & Collecting Data Scientists use the metric system to collect data. The metric system is a universal measurement system based on the number 10: The meter is the distance value. The gram is the mass value. The liter is the volume value.

A centimeter is 1/100 of a meter. Kilo- K 1000x Hecto- h 100x Deka- da 10x Unit (m, L, g) - 1 Deci- d 1/10 Centi- c 1/100 Milli- m 1/1000 A kilometer is 1000 meters. A centimeter is 1/100 of a meter.

Larger Unit  Smaller Unit Conversions If you want to change a larger unit into a smaller unit, move the decimal place to the right. Larger Unit  Smaller Unit 10 km = 10,000 m 2 m = 200 cm

Smaller Unit  Larger Unit Conversions If you want to change a smaller unit to a larger unit, move the decimal point to the left. Smaller Unit  Larger Unit 100 m = .1 km 2,000 cm = 20 m

Graphing How a scientist shows patterns in data collected There are several types of graphs; not all of them are useful for data communication. Which type of graph is appropriate for which situations?

Line Graph Compares 2 things in which items on 1 axis affect the items on the other axis If you are comparing anything to time, it is usually a line graph. Example: the temperature in NYC over several days

Bar Graph Compares 2 or more values Example: students’ favorite colors

Pie Chart Shows proportions or percentages of a whole thing Example: comparing the percentages of crops sold in the US

Components of a Graph – LABEL!! Title: give your graph an appropriate title Horizontal Axis: label & give scale Vertical Axis: label & give scale Key: give meanings of symbols & colors used Data Points: label all of them clearly

Conversions & Graphing Practice Practice converting meters (unit of length). Use the data given to create a graph. Which type of graph would be most appropriate?