Showing posts with label assessment. Show all posts
Showing posts with label assessment. Show all posts

Sunday, January 15, 2023

Making it harder to cheat

Here is the problem: teachers want to engage their students with interesting demonstrations and activities to motivate them to think about  a scientific concept. Students, on the other hand, just need a good mark on the tests and assignments so they can become a doctor, or a lawyer, a cobbler or a candlestick maker, etc.

As the technology available to students to help them answer their assignment questions gets better, teachers need to think about how to structure questions to make students think, rather than just google the answer.

Here is an example of a pretty standard sort of test/assignment question; What properties of aluminium make it suitable for use in cooking pots.  Give a disadvantage of using aluminium for pots.

If you copy and paste that into google, there are 2,090,000 results, and the top of the page will read, "Aluminum is lightweight, cheap and very good at distributing heat. It doesn't retain heat particularly well though, so the temperature will fluctuate as food is added to a hot pan. It's also the softest metal on our list, so it will scratch and dent pretty easily."

Assignment done! No thought required!

So we need to re-structure the question. How about this...

On the planet P42da, the element potsnpanium is used to make large pots in which the P42daians heat soup to above the boiling point of liquid water at 1 atmosphere. What properties of potsnpanium make it suitable for this purpose. Give an example of a safety precaution the P42daians should take when handling potsnpanium pots. Describe a way to reduce this hazard.

Copied and pasted into google this yields 0 results and a heap of useful suggestions:

"

  • Make sure that all words are spelled correctly.
  • Try different keywords.
  • Try more general keywords.
  • Try fewer keywords.

"

Might force some students to have a think about it.

Sunday, June 7, 2015

Buy and Sell Essays

If you want to know where to go to buy a high school-level essay suitable for use in Australia, the Sydney Morning Herald has a number of suggestions, with some indication of prices:
http://www.smh.com.au/national/education/cheating-endemic-in-nsw-high-schools-20150607-ggw8h9

A couple of years ago I went to a high school science teachers workshop, where, over lunch, I shocked a number of teachers of physics and chemistry by telling them how easy it was for students to buy their "extended experimental investigation" online, and, how cheap it was. My point in doing this was not to shock the teachers (I thought everyone knew about this), it was to point out that the notion of using this type of investigation as an assessment tool was not assessing students' scientific abilities it was only assessing their ability to find relevant information online (arguably just as important and useful in its own right). Unfortunately, as an assessment tool, it also favours those with money to spend. The answer is not to try to "crack down" on this "cheating", which, although possible would almost certainly not be practical, rather the answer is to change the way students are assessed.

There is probably a much more deeply-rooted problem in all of this "cheating". I strongly suspect that for many students, there is no joy in learning or indeed in trying to understand concepts, the only purpose for going to school and doing assessments, is to get a good mark in order to go somewhere else after school (university, TAFE).(No doubt, the only reason they want to go to a tertiary education institution is in order to get a good mark in order to go somewhere else again ..... and it is entirely possible they will spend the rest of their lives being dissatisfied and buying their way to "somewhere else").
Perhaps if we could take everyone's focus off "assessment", and get them to focus on "learning", students might find that not only is there a lot of fun to be had out of learning something new, there is also an intense sense of satisfaction when you realise that you now understand a concept well enough to use to it in different situations, and, there is an enormous sense of power in using your understanding to make and test predictions. They might even find the learning process enjoyable.

Saturday, January 19, 2013

What is a Search Engine?

If you want to find information, what is the first thing you do?

You will probably use your smartphone, tablet, laptop, notebook, netbook, or some other "computer", to connect to the internet and then type your question into a search engine.
You've probably used one of the popular search engines such as google, yahoo or bing, but there are hundreds of search engines to choose from (you can visit http://www.thesearchenginelist.com if you would like a lengthy list of search engines).

A search engine can be a useful tool for helping you find information, as long as you enter an appropriate search term. In other words, if you ask a silly question you will get lots of silly responses (known as garbage in, garbage out, or GIGO).

It is important to realize that a search engine is NOT a person, a search engine can not answer your questions.
A search engine is NOT an encyclopedia, it does not give you specific information related to your question. Search Engines do not write their own pages of information.
A search engine is NOT a dictionary, it can not define a term for you and give you examples of usage. Search engines do not write their own definitions or examples.

So, what is a search engine?
A search is just a computer program that acts like a library catalogue or the index of a book.
Pages on the internet containing information are categorized by the search engine, just like in a library catalogue or the index of a book.
When you type in your search term, or question, the search engine matches your term, or question, as closely as possible to the pages of information on the internet that it has catalogued or indexed.

So what? Who cares?
You should!
In order to successfully use a search engine to find what you want, you need to understand what it is (and what it is not) in order to understand what it can do (and what it can't do).
Let's take a look at some examples.

1. A Search Engine is NOT a Person
a) The term with multiple meanings
Example : mole
Your chemistry teacher will tell you that a mole is defined as 6.02 x 1023 "things", or as the molecular mass of a substance expressed in grams.
If you type mole into your favourite generic search engine (eg, google, yahoo, bing) you will end up with a list of links to pages of information on the internet about various types of moles including the chemical definition of a mole, the mole as an animal, the mole as skin blemish (moles and freckles), mole as a Mexican sauce.
The search engine is not capable of interpreting your question and putting it into context like a person can.
If you ask your chemistry what a mole is, the chemistry teacher assumes you are talking about a chemical mole.
If you ask your biology teacher what a mole is he or she will probably ask you for more information (what sort of mole do you mean).
If you ask a medical doctor, he/she will probably tell you about skin blemishes.
As a cook about mole, they'll start talking about sauces.
A search engine cannot guess what type of mole you are interested in because a search engine is not a person.

b) "The homework answer"
If you ask a person what a + 2a is if a is equal to 2, they will probably 6, and your maths homework is probably done.
Now, type a + 2a if a is equal to 2 into your favourite search engine. What do you get? You get a list of pages on the internet, probably maths related, which include reference to a, +, and 2a.
The search engine cannot answer your homework question if you treat the search engine like a person.

c) "The homework question"
If you stand in front of someone and ask, "happy?", they will probably assume you are asking them if they are happy and respond to the implied question by saying something, "Yes. I'm happy."
A search engine cannot interpret the question, so a search engine does not know if you asking for a definition of the word happy, or if you are asking it if it is happy, or if you are asking about movies that have happy in the title etc. You can prove this to yourself just by opening up 2 windows with your favourite search engine open in each and typing "happy" into one and "are you happy?" into the other.

d) Spelling Mistakes and Typos
Spelling is important in science, and it can be critical in chemistry.
If you have been asked to find out about ethene, but you type ethane into your search engine, your search engine will list resources dealing with ethane NOT ethene. The search engine does not know you have made a spelling mistake or typo because both ethane and ethene exist.

e) Asking Nonsense
You type nonsense into a search engine's textbox it will provide you with a list of links to resources on the internet that make reference, in some way, to the nonsense you have typed in. A person would know you are asking nonsense, but a search engine is not "intelligent", it can't decide that what you are asking is nonsense.
For example, if you ask a person  how old Jo is if John is Jane's brother they'll tell you this is nonsense, but if you type how old is Jo if John is Jane's brother into the textbox of a search engine, you'll end up with millions of links to pages that reference Jo, John, Jane, brother, old, etc.

2. A Search is NOT an Encyclopedia nor is it a Dictionary
A search engine is not a "resource", it is only a tool.
An encyclopedia is a resource, it provides information that you can use.
In order to find the information you want in the encyclopedia you can use its index, the index is a tool.
Pages on the internet contain information, these pages are the resources.
A search engine is a tool you can use to find the resources.
If you have been asked by your chemistry teacher to find out about quicksilver, and you type "quicksilver" into your favourite search engine, the search engine gives you millions, of links to pages on the web that make reference to quicksilver. In order to get the information you will need to click each link.

There are ways to ensure that you don't put garbage into a search engine, which should reduce the amount of garbage the search engine gives you, but we'll deal with that another day.

Practice Questions
Which of the following questions are most likely to be appropriate search terms or questions (things you could type into a search engine that would result in links to web pages that contain similar sorts of useful information)? Explain your decision in each case.
  1. What is the red dot in the diagram?
  2. multiplication
  3. mathematical multiplication
  4. What is induction?
  5.  mathematical induction
  6. What is the answer to question 4 on page 91?
  7. How many moles are in x grams of NaCl?
  8. How long does it take to melt ice?
  9. What is the chemical composition of ice?
  10. What is the chemical composition of solid water?
The examples below are actual search terms that real people have typed into a search engine
In each case, explain why it is NOT an appropriate search term.
  1. if the density is 4.70 g/cm3, then calculate the metal's atomic weight
  2.  chemical bond energy in steel
  3. how to calculate kj per mole
  4. N2- on conceptual level
  5. 100 parts a to 3 parts b by weight
  6. 35.    how would the following elements become chemically stable?  (which ion would they form?) a.cl b. na c. al
  7. how to find empirical formula by making table
  8. how to calculate masses of reactants and products
  9. which of the following is the best estimate of the percent abundance of the two isotopes of copper?
  10. for each of the following balanced reactions calculate how many moles of each product would be produced by complete conversion of 0.50 mol of each reactant