Experimental Validity & Class Effort

Experimental Validity & Resulting Conversation

In class today, we discussed the concept of validity as it pertains to experimentation.  Due to the fact that many students could not accurately answer a question pertaining to validity on their last VDA (#6), I thought I would spend a class period discussing it.

As part of our conversation, we discussed social phenomena and their effect on an experiment's results. I mentioned reading an article about how humans relate to machines.  In addition, we discussed a classical psychological experiment that Milgram performed in 1961.  Both experiments are heavily influenced by the times in which they were performed.

Effort

In an effort to deliver students and parents an accurate picture of their students' performance, I have decided to give each student two grades for science.  The first grade will be a reflection of your students' performance in the content area.  Specifically, it will reflect the grades they earn on the homework.

The second grade they will earn in science will be contingent upon their effort in class.  This grade will be determined by calculating a pass (100)/fail (0) for each assignment.  If they turn the work in, on time AND complete, then it will receive a 100%.  If not, it will earn a 0%.  To be clear, if they turn in an assignment two days late, they will receive appropriate credit for the assignment, but their science effort grade will suffer the 0%.

Example:

Student A turns in the following assignments:

Assignment 1
earned: 100% (missed 0 questions)
turned in: on time (100% effort)

Assignment 2
earned: 80% (missed 2 of 10 questions)
turned in: late (0% effort)

Assignment 3
earned: 90% (missed 1 of 10 questions)
turned in: on time (100% effort)

Assignment 4
earned: 100% (missed 0 questions)
turned in: late (0% effort)

Assignment 5
earned: 70% (missed 3 of 10 questions)
turned in: late (0% effort)

Their grades would be as follows:
earned: 88%, B+
effort: 40%, F

What that means for you, parents and students, is that you know the student would have likely earned a higher grade if they put more effort into the class.  Whereas, if a student earns an 88% and has an effort of 100%, you can be confident that your child worked to the best of his/her ability.

Please note: my class grade is weighted by category whereas the effort grade will not be weighted.

Extra Credit Reminders
1)Page 177 Challenge: Create a power point answering all of the questions.  The more effort you put into the presentation, the more points you will earn.  (Due: Monday, February 4th)

2) Wrinkly finger experiment:  Put one hand in salt water, the other in fresh water.  Be sure that temperature and time of exposure is constant.  Take photographs of your finger tips and upload them to your blog.  (Due: Friday, February 1st)

Shakespeare's in Your DNA

Today we read this article.  During our lesson, students learned the following:

Binary Code is the code that our computers "speak".  It's a series of 0s and 1s that computer scientists use to tell computers what to do!

DNA PCR or DNA polymerase chain reaction, is a process by which geneticists take a small amount of DNA and copy it so that they have a larger amount.  This makes it so that they can run a slew of tests on the DNA without needing a human to give a large sample.

new vocabulary:

redundant: an adjective that describes something that is repetitive.  "Redundancies" is the plural form.

cipher: a tool used to break or create a code.  

archives: data storage, often organized by type (example given: the library of congress holds our nation's important archives)

intact: something that is whole, or in its original form

sequence: the order of something

synthesis: to make or create something (example given: synthetic materials are man-made materials)

exponential: something that is multiplied by itself (example given: exponential growth refers to growth that doubles over a unit of time.  Specifically, if we have daily exponential growth, and we start with 2 of something, on day two we will have 4, the following day we will have 16, etc.)

decipher: a verb that means to break a code

waived: to pass on something (example given: waiving fees for an activity)

If you would like to learn more about binary code, you can do so here.

Students, questions?  Comments?  Leave them here...

VDA # 6: Prune Fingers!

VDA #6

Prune Fingers!

due: Friday, January 25th (11:59pm)

Please read the article found here and then address the following questions.  Your responses must be in complete sentences.  Complete sentences contain a subject (a noun, real or implied) and a predicate (verb) and form a complete thought. 

*Be sure to copy and paste the questions into your own blog post prior to answering the questions.  In addition, be sure to put a title on your blog post that indicates this is VDA #6.

1. Scientists predict that prune fingers may serve a purpose.  What purpose do they suggest prune fingers serve?

2. Do you think that the study performed in England was a valid study?  Why or why not?  

3. How would you design an experiment to gather more data to support the suggestion that prune fingers serve a purpose?   (Be sure to include the number of people sampled, the independent and dependent variables and the duration or amount of time for your experiment.)

4. While scientists are attempting to determine the biological purpose for prune fingers, the article does not discuss why prune fingers happen in the first place.  What biological process allows for the skin on our hands and feet to turn wrinkly when submerged in water for long periods of time?