Creating Bar Graphs that Show Standard Error of the Mean

Below are two video tutorials that show you how to calculate standard error of the mean (first tutorial) and how to create a bar graph with customized error bars.  Watch each tutorial to learn how to make your graphs for the acorn lab.

How to calculate standard error of the mean and set up a table to create a bar graph

How to create a bar graph that compares two means and shows customized standard error bars

Copy and paste your graph into a word document, write your name, the date, a place for a page number and the heading "Acorn Post Lab Questions" then answer the questions below:

1. Compare the size of the standard error between your sample and the overall class sample.  Which standard error is smaller?  Why?

2. Identify one source of natural variability in your data.

3. Suggest a reason for how this variability could impact your data.

4. Identify two sources of experimental variability in your data.

5. For each source of experimental variability you identified, explain how it could impact your data.

6. What do the standard error of the mean bars (I) on your graph represent?


Save this document as "acorn post lab questions."

Print it out and bring it to class on Tuesday.

Transitioning from Climate Change to Evolution

Today we didn't have lab, so we used our long block to dive into evolution.  In order to transition from climate change to evolution, we used data from Stirling and Parkinson (2006), showing decreasing lone female polar bear body mass over time.

http://tinyurl.com/9llchun

Examining this graph also gave us the opportunity to revisit independent and dependent variables as well as start to talk about expressing variation in data.  We tried to come up with the causes for the decrease in weight over the years (as we learned later in class, the environment can play a big role in determining if a trait is beneficial for an individual).

Before we could dive into learning about evolution, we needed to clarify the terms evolution and theory.  These words have a very different meaning in science, than they do in other disciplines. 

We watched the videos below.

To see variation in a population for ourselves, we visited the finches and made observations about the variation that we saw.

Homework:  Read the article "Attack of the Mutant Crickets!" and answer the questions on page 6.

The science behind a climate headline

Today we discussed what makes a source credible.  We compared the two editorials you read for the info lit assignment and you had to defend an article's credibility.   At the end of class we watched the four minute TED talk on The Science Behind a Climate Headline.

Homework and a Reminder: Your 3-2-1-R is due Sunday by 8PM.  On Tuesday you will have a mini-mental inventory on global warming and climate change.  Review your notes and handouts.  This will be a way for me to see what you have retained about climate change and global warming.

Climate Change

We hear the words "climate change" and "global warming" all the time, but what do these terms actually mean?  Are these terms synonymous? No!  Global warming is NOT synonymous with climate change.  We started today off by discussing what you know about each of these topics and one of you admitted, "well they aren't what I thought they were...."

The Earth's climate is changing and "Global surface temperatures have increased about 0.74°C (plus or minus 0.18°C) since the late–19^thcentury (NOAA, 2012).  One of the causes of this an increase in greenhouse gasses, such as carbon dioxide and methane.  To help us visualize greenhouse gasses, we watched the clip "None Like It Hot."  Part of being a good scientists is being able to distinguish facts from opinion, and from that clip you gleaned that greenhouse gasses trap "Mr. Sunbeam" that would otherwise radiate back into space.  You can see what actually happens to photons here. 

How much CO2 is in the atmosphere and how much able to be removed through photosynthesis?  Check out the climate change bathtub simulation below.

Click to get to the simulation

Why does this matter?  How will this affect what lives where and why?  Some turtles sex is determined by the temperature of its surroundings while it is in development.  For birds, an increase in temperature can change their migratory patterns. 

You examined a version of this data today.  What are these two graphs telling us about predator-prey relationships and the effect of climate change?

Homework: Complete all of the remaining questions in the Ecology questions packet.

Photosynthesis

As we discovered on Thursday the pond is filled with phytoplanton that perform a process called photosynthesis.  Today we learned more about this processes as well as practiced identifying the independent and dependent variables in an experiment.

Homework due Tuesday:
Read pages 136-139 and answer questions 1,2,3, 4 and 7,8,9 from the 2FS Ecology Homework packet.

Reminder: Your 3-2-1 is due by Sunday at 8PM.

Here's the song we watched in class to give us an overview of Photosynthesis.

Evaluating data and van Helmholt

Today we looked for patterns in our data from the Sampling the Environment lab yesterday.  For homework  finish the post lab questions.  You have been emailed a link with the class data in a google doc.

In discussing our sampling yesterday we discovered that not everyone used the exact same method.  This led us to a discussion of controls and variables.  After warming up with some Simpson's variable problems, we got down to business used the Van Helmholt worksheet to look controls and variables in relation to photosynthesis.  If you did not finish the van Helmholt worksheet in class you need to finish that as well.


Reminder: On Sunday, your 3-2-1 reflections are due.