Collecting & Graphing Data

Test tubes and Bunsen burners With the person next to you in lab, decide who is going to be the test tube and who is going to be the Bunsen burner

Objectives SPI 3210 Inq.3 Determine the appropriate tools to gather precise and accurate data SPI 3210 Inq.4 Evaluate the accuracy and precision of data SPI 3210.T/E.1 Distinguish among tools and procedures best suited to conduct a specified scientific inquiry Enrichment Objective: Use significant digits when recording data in the lab

Valid & Reliable Data Valid = It is a truthful and accurate representation of the real world. It measures what it is supposed to measure. Is it void of bias? Reliable = This means that a result is obtainable time and time again. It is reproducible.

A broken scale Your bathroom scale is broken and adds 5 lbs to the weight it measures. Is it valid? Is it reliable?

Test Tubes Explain to your partner the difference between a valid and a reliable result.

Reliability of Data Accuracy refers to the closeness of a measurement to the correct or accepted value. Precision refers to the closeness of a set of measurements to each other (consistency).

Three students were asked to determine the volume of a liquid by a method of their choosing. Each student performed three trials. The table below shows the results. The actual volume of the liquid is 24.8 mL. Trial #1 Trial #2 Trial #3 Student A 24.8 mL 24.6 mL Student B 18.5 mL 18.6 mL Student C 22.3 mL 23.1 mL 19.7 mL Which student is accurate in his measurements? Which student is precise? Are any of the measurements valid? Are any of the measurements reliable?

Bunsen Burners Explain to your partner the difference between accurate and precise results

Objectives: SPI 3210 Inq.3 Determine the appropriate tools to gather precise and accurate data SPI 3210 Inq.4 Evaluate the accuracy and precision of data SPI 3210.T/E.1 Distinguish among tools and procedures best suited to conduct a specified scientific inquiry Enrichment Objective: Use significant digits when recording data in the lab

Collect Data Data = recorded observations Two Types of Data Quantitative Data- data that involves numbers or measurement Example: The length of the plant is 18.5 cm Qualitative Data- descriptive data that does NOT involve numbers or measurement Example: The Listerine has dark blue color; while, Wal-Mart and Scope are lighter blue.

Test tubes and Bunsen burners Partner time Test tubes explain what quantitative data is. Give an example that is not in the notes Bunsen burners explain what qualitative data is. Give an example that is not in the notes

Graphing Once data is collected, scientists usually organize the data into charts and graphs. Charts and graphs allow scientists to analyze the data more easily. Line graphs and bar graphs are the two most common types of graphs used by scientists.

Inferences Scientists often draw inferences from data gathered during experiments. Inference- conclusion made on the basis of facts and previous knowledge rather than on direct observations. Unlike a hypothesis, an inference is not directly testable.

Evaluating Results By analyzing data tables and graphs, scientists can draw a conclusion whether or not a hypothesis is supported or not. If supports, then retest. If does not support, revise hypothesis. An experiment can only disprove, not prove a hypothesis. If results favor the hypothesis, it is said the hypothesis was supported.

What can you infer from the information in each chart? Line Graph What can you infer from the information in each chart? Bar Graph

Where do the variables go on a graph? When graphing, the independent variable is on the x-axis; while, the dependent variable is placed on the y-axis.

Graphing Practice Test tubes and Bunsen Burners work together to complete the graphing practice worksheet

Lab In today’s lab, we will measure materials using different instruments. The goal is to find the most useful and precise instrument for the type of data we are trying to collect.

Test tubes and Bunsen burners Wrapping up lab Test tubes: explain the difference in precision between a graduated cylinder and a beaker Bunsen burners: Explain the difference between accuracy and precision

Objectives: Did we do these?? SPI 3210 Inq.3 Determine the appropriate tools to gather precise and accurate data SPI 3210 Inq.4 Evaluate the accuracy and precision of data SPI 3210.T/E.1 Distinguish among tools and procedures best suited to conduct a specified scientific inquiry Enrichment Objective: Use significant digits when recording data in the lab