Bellwork Sept 14, 2015SPI 0807.Inq.5: Cause and Effect

1. Which most likely causes the paper to spin?

2. By inserting a gene into crop plants, scientists have developed plants that are resistant to insects. If an insect eats the plant, the insect dies. Which practice is unnecessary with this new plant variety?

a. spraying plants with pesticides b. overproducing food crops c. removing weeds from crops

3. A student filled three identical cups with equal amounts of water. The student placed each cup in a room with a different air temperature. After a few days, the student compared the amounts of water remaining in each cup. What cause-and-effect relationship does this investigation support?

Bellwork Sept 14, 2015SPI 0807.Inq.5: Cause and Effect

1. Which most likely causes the paper to spin?

2. By inserting a gene into crop plants, scientists have developed plants that are resistant to insects. If an insect eats the plant, the insect dies. Which practice is unnecessary with this new plant variety?

a. spraying plants with pesticides b. overproducing food crops c. removing weeds from crops

3. A student filled three identical cups with equal amounts of water. The student placed each cup in a room with a different air temperature. After a few days, the student compared the amounts of water remaining in each cup. What cause-and-effect relationship does this investigation support?

Heat rising

A

Higher the temperature, the more the water evaporates

Today's Plan

Plan

1) Do and review Bellwork2) Go Over Objectives3) Quick Review over cause and effect4)Quiz over cause and effect5) Notes on Bias and error

WRITE THIS IN YOUR AGENDA!Homework: NONE

Sept 14, 2015SPI 0807.Inq.5: Bias and Error

Notes

Bias and Error in ScienceBias: this means you are prejudiced towards or against something and that you allow your views to affect the results of your experiment.

Bias Is Bad!

Bias

Science is about obtaining accurate resultsso bias should NEVER be allowed to influenceyour experimental results!

Bias

ScienceSPI 0807.Inq.5: Bias and Error

Instructions1) First click on "View" from the top-menu bar.2) Then click on "Slide Show" from the drop-down menu.3) Then use the right-arrow button on your keyboard to advance through this presentation.

Notes

Bias in Science ExperimentsExample: Imagine that you doing an experiment to determine which NFL football quarterback can throw a football the furthest.Your favorite football team is the Tennessee Titans, so you are disappointed with your data when you notice that the Titans' quarterback's throwing distance is not the furthest. Yet because this is your favorite quarterback, you change the data so that this quarterback appears to throw the furthest.

ScienceSPI 0807.Inq.5: Bias and Error

This is BIAS, and it should NEVER be allowed in science.

Example: Bubba loves to eat french fries with lots of extra salt. He conducts an experiment to determine how much better french fries taste with lots of extra salt.

Identify the bias or error in this situationANSWER: Because Bubba likes extra salt on his fries, hewrongly assumes that everyone else will like extra salt too.He is biased toward salt, so his results will contain errors.

Notes ScienceSPI 0807.Inq.5: Bias and Error

BIAS should NEVER be allowed in science experiments!

Two students who love Justin Bieber’s music do an experiment to measure how long people have to hear one ofJustin’s songs before they too fall in love with his music. Question: Which choice below most likely will occur?

(Just write the correct letter)A) Bias B) Fraud and Waste C) Song and Dance

Notes

Bias in Science

Answer: These two students are biased towards Justin Beiber, so their results will probably be biased and wrong too

ScienceSPI 0807.Inq.5: Bias and Error

BIAS should NEVER be allowed in science experiments!

Humans are imperfect, so bias happens both intentionally and unintentionally

Notes

Solutions to Bias in Science

ScienceSPI 0807.Inq.5: Bias and Error

Ways to Reduce and/or Eliminate Bias Be aware that bias can and does happen Strive to recognize it, and eliminate it from your

experiments. Follow the steps and principles of the scientific method Make sure that others rigorously review your work

looking for bias

Notes SPI 0807.Inq.5: Bias and Error

Famous Bias in Science

Science

Thomas Edison and Direct Current Electricity

Inventor: Thomas Edison

Notes SPI 0807.Inq.5: Bias and Error

Famous Bias in Science

Science

Direct Current vs Alternating Current

Bias:

Edison promoted direct current electricity, but Nikola Tesla promoted alternating current for the Westinghouse Electric Company.

Experiments had clearly demonstrated that alternating current was more efficient and less expensive. Yet Edison refused to yield to facts.

Nearly all electricity generated today is alternating current

Avoid Mistakes: One small error can result in all your experimental data

being wrong So scientists work very hard to avoid making mistakes

Peer Review: One key way scientists deal with this issue is by having

other scientists review their work to check for mistakes This very common practice is called peer review

Notes SPI 0807.Inq.5: Bias and Error

Errors in Science

Science

To Avoid Mistakes: Make sure you are following the steps of the scientific

method Make sure you have only one independent variable at a time Make sure you correctly identify your dependent variables Make sure you include valid control experiments Make sure you record in detail every step of your

experiment Ask someone else to review all your work (peer review)

Notes SPI 0807.Inq.5: Bias and Error

Errors in Science

Science

Notes SPI 0807.Inq.5: Bias and Error

Famous Errors in Science

Science

Mars Climate Orbiter:

Notes SPI 0807.Inq.5: Bias and Error

Famous Errors in Science

Science

Mars Climate Orbiter:

Expensive Mistake:

launched by NASA in December 1998, this robotic spacecraft was designed to study weather on Mars.

A design team used standard units (pounds- seconds) while a different design team used metric units (newtons- seconds). So instead of orbiting Mars, the spacecraft crashed to the surface of the red planet.

Cost of this mistake: $327 million dollars

Notes SPI 0807.Inq.5: Bias and Error

Famous Bias and Errors in Science

Science

Canals on Mars

Astronomer: Percival Lowell

Notes SPI 0807.Inq.5: Bias and Error ScienceFamous Bias and Errors in Science

From 1894 to 1908 Percival studied the planet Mars with a large telescope.

He wrongly concluded that the features on Mars were canals built by extraterrestrials (Martians)

Notes SPI 0807.Inq.5: Bias and Error Science

Percival was fascinated about the possibility of intelligent life on Mars .

He was biased about this.

He observed hazy images of the surface of Mars

His bias lead him to make significant errors about what he saw.

Later observations by others confirmed that there are no signs of intelligent life on Mars.

Famous Bias and Errors in Science