1. Textbook Fail and Finesse
Olexandr Andriyashchenko
EDU 6530

2. Summary of lesson:
Students use prior knowledge and acquire new skills in order to balance redox (oxidation-reduction) reactions by half-reaction method through teacher’s demonstration and then by collaborative work.
Learning target: I can apply steps of half-reaction method to balance redox (oxidation-reduction) reactions that involve only two reactants.

3. Classroom context of textbook fail:
This lesson is intended for high school AP chemistry course and lasts 55 minutes.
Is taken by sophomores and seniors.
Students’ strengths: have solid knowledge of previous chemistry content and concurrently take biology or have already passed it. Students can also write symbolically and apply their skills for abstract reasoning. Can also read complex passages if they have a reasonable amount of text and include pictures (diagrams).
Students’ needs: need scaffolding and activation of prior knowledge, otherwise they struggle since concepts are complex and require gradual uncoverage. Students also stumble and have reading difficulties if a passage has too much text with little or no pictorial (diagrams) component.

4. The text:
Chemistry: The Molecular Nature of Matter and Change by Martin S. Silberberg (2000), 4th edition.

5. Lesson plan:
This is a 55 minutes lesson for AP chemistry course.

6. Intrinsic reasons for textbook fail:
The sample problem in the textbook chosen for this lesson (next slide) contains dense text with no diagrams or even arrows for better clarity.
Absolutely no visual helping cues.
Several steps were combined into one step in order to save space instead of showing them in details for better understanding.
No explanations were given on how to compute overall charges of left and right sides of half-reactions.
Almost no math is shown in the text whish makes it difficult to conform to HS-PS1-7 standard that emphasizes manipulation and usage of mathematical principles.

7. Intrinsic reasons for textbook fail:
Just look at how dense this text is!
Students are not presented with tips on calculations for computing of overall charges of left and right sides of half-reactions.
Yet, the ability to accurately calculate those charges is essential because even with high degree of ability you can easily miscalculate them and end up balancing the whole reaction incorrectly because you did not use explicitly written mathematical approach shown in my hand written approach!

8. Intrinsic reasons for textbook fail:
Next slide shows the difference in the density of text and amount of visual cues (arrows and horizontal curly brackets) between my own scaffolded and detailed way of balancing this reaction and that of the text.
The text uses no arrows and horizontal curly brackets for clarity.
The text contains too much text and it combines several steps into one.
The text shows absolutely no math – the author assumes you get it.
I use visual cues (arrows and horizontal curly brackets).
I use much less text, and yet what’s left precisely shows my reasoning.
I use straightforward explicitly written math underneath the brackets for clarity.
My example (handwritten) is on the left and the text is on the right.

11. Student feedback that the textbook failed:
Students were puzzled when I demonstrated them the example of balancing the reaction using the way this text presented it.
2 students made inappropriate comments at complexity of this example.
During informal assessment after introduction of the half-reaction method 1 student asked why is it so complex.
I asked if other students had the same feeling and about 10 of them confirmed they do.
I asked students what specifically they do not understand and 2 of them said on behalf of the whole class that they simply got lost.
No specific information was provided by students about their difficulties, so it tells me that I need to modify the instructional approach completely.
So many faces expressed confusion and frustration.

12. How I finessed learning:
Instead of using the way the text presents the balancing method I rewrote it a way to show more math but less text.
I demonstrated to students how to balance the redox reaction using my approach.
I demonstrated that there could be less text, more visual cues (arrows and curly brackets) and math.
I did not combined several steps into one. This eliminates confusion. We went step by step and I mathematically explained why I had this result and not something else.
My approach also has more empty space and nothing is crammed.

13. The new learning target:
How about this new learning target:
I can apply steps of half-reaction method to balance redox (oxidation-reduction) reactions that involve only two reactants by using arrows, curly brackets, uncombined steps, and explicitly written math.
The new LT is more specific and lists approaches completely omitted by the text.

14. Evidence that students finally learned:
When I was explaining balancing the redox reaction students seemed to be more interested.
More of them appeared to be writing down my example.
After explaining to them my approach step by step I asked students if they have any questions and this time their questions were specific.
1 student asked me to go over determining overall charges of left and right sides of half-equations one more time.
1 student asked me why multiply one of the half-reactions by a whole number.
1 student asked me how do we know if this reaction is acidic.
There were no more inappropriate comments.

15. What I learned:
I need to recognize in advance whether or not a method of doing something (balancing reaction or doing a calculation) needs to be refined or scaffolded.
There should be absolutely no omission of steps by combining them into one or several steps.
Visual cues help a lot and the more visual information the better and learning becomes easier.
Textbook could and should be consulted but it should not be strictly adhered to in every way in terms of presenting information since it was written in difficult and dense language with the assumption that anyone can understand the material.
Too often the text shows too little math and it might not be obvious how an answer was computed.
More straightforward math actually simplifies computing an answer if the math itself is not difficult.
Do not cram writing.

16. What I learned: Just be honest with you students.
Do not reprimand or make them feel bad if your explanation is confusing to them even if you explained the way your text did.
Be ready to admit your mistakes.
Take time to reflect and analyze reasons for confusion.