Writing a Lab Report

A blueprint for

Experimental design success.

HEADER Line one- Give the experiment number,

experiment title, date Line two your name, lab partners, team number

and block number

INTRODUCTION

Paragraph that sets the stage for you experiment. It gives the reader enough information to understand your objectives. Start with current knowledge about the subject and narrow down to your specific experimental problem

Problem/Purpose

Question to be solved. Must be about something measurable.

– Why?– How?– What?

HYPOTHESIS

Prediction of answer in the future verb tense

Use If, then statements

If ____ [I do this], then _____ [this will happen]

MATERIALS

Detailed list the equipment Detailed list the equipment needed to perform the needed to perform the experimentexperiment

PROCEDURE

Detailed steps or directions on Detailed steps or directions on how to DO the experimenthow to DO the experiment

Includes repeated trialsIncludes repeated trials Watch for cautions and safety Watch for cautions and safety

symbolssymbols Directions found on

lab sheet

VARIABLES

Identify the 3 types

of variables

A variable is any factor in an experiment that can be changed

What is a variable?

Example: Suppose you want to determine how high a ball can bounce

Variables that would effect the ball bouncing would include: type of ball, size of ball, surface, height from which it is bounced, force

Variables are classified3 types of variables Independent variable (manipulated)

factor being tested Dependent variable (responding)

factors that measures the result of the change

Controlled variable (constant)

all other factors that are kept the same

OBSERVATIONS

Observations can be made directly with the senses or with the use of measurement tools and technology

Types of observations:

1. Qualitative Observations-describe

2. Quantitative Observations-measure

QUALITATIVE Observations Deals with descriptions. Data can be observed but not measured. Colors, textures, smells, tastes, appearance,

beauty, etc. Qualitative → Quality

Qualitative Example

smells old and musty texture shows brush strokes of oil paint peaceful scene of the country masterful brush strokes

QUANTITATIVE Observations

Deals with numbers. Data which can be measured. Length, height, area, volume, weight,

speed, time, temperature, humidity, sound levels, cost, members, ages, etc.

Quantitative → Quantity 

Quantitative Example

picture is 10" by 14" with frame 14" by 18" weighs 8.5 pounds surface area of painting is 140 sq. in. cost $300

???? WHICH TYPE OF OBSERVATION???? qualitative (general) or quantitative (specific).

It is cold outside._____________________________

Jack is 165 centimeters tall.____________________

The temperature is -10 degrees Celsius.__________

The sky is covered with cumulus clouds.__________

The ball is heavy.___________________________

DATA information collected during experimentation (includes data tables, graphs, and calculations)

DATA TABLES Used to list and collect information Organizes data collected from multiple

trails

DATA TABLE BASICS Independent variable LEFT, dependent variable RIGHT

Titles for table and each column

GRAPHS

used to show trends of the data

increasing decreasing

GRAPHING BASICS

The independent variable is always on the X-axis (horizontal) the dependent variable is always on the Y-axis (vertical) TITLE EVERYTHING!!!! Each graph must include a graph title, Y-axis title and units X-axis and units

GRAPHING BASICS

Dependent variableName and unit

Independent variableName and unit

Graph title

Data table example

TYPES OF GRAPHS

The type of data collected will determine which graph is to be used.

Types of graphs include bar graph, circle graph and line graph

Bar Graphs

Bar graphs are used to show a comparison of multiple types variable is The independent variable is described and the dependent variable is counted

CIRCLE GRAPHS

Also called pie graphs

Pie graphs are used to compare the parts of a whole.

Shown as a percentage

Total must equal 100 %

Line Graphs

Line graphs are used to show the relationship between variables

each variable has numbered units

Show all work!!!

1.Include the formula

2. Plug in the data

3. Solve the problem with correct units

CALCULATIONS

Calculation Model

Formula used s = d/t Plug in values s= 20m/5s Solve s = 4 m/s

CONCLUSION

Compose a paragraph that describes --- what you learned from the data you collected It states trends or patterns you see in the data and anything else you learned from the data Reduce the numbers/measurements to averages in sentence form Determine if the hypothesis is accepted or rejected. If hypothesis is rejected, give possible reasons for the

difference between your hypothesis and the experimental results

Discuss any problems that may have influenced your outcome and suggestions for improvement.

End with a closing statement about your findings.