This weekend, meteorologists predict we’ll see one to three inches of snow followed by temperatures only inhabitants of the Yukon territory should experience. With a forecast such as this, you need to know the best routes so you can complete all of your weekend responsibilities, whether you are working or getting all of your errands out of the way. And it doesn’t help that we seem to be getting snow every weekend! You do not want to get stuck, not when the warmest socks and the warmest boots will not do. So what roads are your best bet?
I grew up with a Christmas experience that I think will be familiar to many in one way or another. I was raised Catholic, so for the first 18 years of my life I did attend mass; this was usually on Christmas Eve, and it was very exciting to me as a child because the church lights would be turned off as the priest walked down the aisle, swinging a thurible filled with smoky incense. It seemed very exotic, not the regular day at church. We would hear the story of the birth of Christ and the three wise men, sing songs, and depending on which mass we were at, there would be a children’s pageant. After, we would go home and have a meal together, and my sister and I would head to bed while my parents stayed up a little longer. In the morning, we would be led from our rooms to the kitchen, eyes covered so that we couldn’t peek at the presents under the tree. Only after breakfast were we allowed to go open the presents; one person was designated to pass out the gifts, and they were opened one at a time. In this way, a good hour or two was spent opening presents and watching others do the same, eventually covering our living room floor with colored paper. Read the rest of this entry »
Thanks to the Reverend Thomas Bayes your inbox is not full of spam.
What does spam have to do with a Presbyterian minister who died in 1761? He was also a statistician and formulated a theorem which bears his name, Bayes’ Theorem. Basically it allows us to adjust the probability of an event given new information that might be related to the event. We can change the probability of an email being spam after getting more information by looking at the contents of the email.
Without Bayes’ Theorem we could look at our inbox and see that on an average day we get a certain amount of spam. The probability that any given email is spam would be the number of spam emails divided by the total number of emails. For example if I received 100 emails today and 70 of them were spam then the chance that any random email would be spam is 70/100 = 70%. But without any more information we still would not be able to predict that any given email was more likely spam than the others. The probability is the same for all of them so not helpful.
But what if we have some new information? What if we know that spam emails often have the word FREE in them? Bayesian Spam Filtering will look through the text in each email, if it finds the word FREE then using Bayes’ Theorem the probability of that being a spam email increases. Spam filters are all a little bit different and look at a variety of things to help them make predictions. Most will have a large list of words, with different weighting, that it looks for. Other things might be if the email has a lot of html tags, the image to text ratio is high, or the subject is in ALL CAPS. The filter is also constantly learning and adjusting the weights by looking at what users have marked as spam. In the end it gives each email a probability and if it is above the threshold set in that filter, then it is automatically marked as spam, put in your spam folder and you do not have to deal with it.
If you are interested in two slightly more detailed examples of Bayes’ Theorem keep reading.
WARNING: MATH BELOW
The basic equation is:
P(B|A) * P(A) P(A|B) = ---------------- P(B)
P(A) and P(B) are the probabilities of A and B by themselves.
P(B|A) is the probability of B if we know A.
P(A|B) is the probability of A if we know B, which is what we are trying to determine.
An intuitive example is if you pull a card from a deck of cards what is the probability that it is a King? We know there are 4 Kings in a deck of 52 cards, so the probability that we drew a King, P(King), is 4/52 or 1/13. Now what if we had some new information about the card? What if we knew that the card we drew was a face card? Now we can use Bayes’ Theorem.
P(Face|King) * P(King) P(King|Face) = ------------------------- P(Face)
We already know that P(King) = 1/13. There are 12 face cards in a deck of 52 cards, which means that P(Face) = 12/52 or 3/13. The last part is P(Face|King). We know that if we drew a King then it is definitely a Face card, so P(Face|King) = 1. Plugging these parts into Bayes’ Theorem gives us:
1 * 1/13 P(King|Face) = ------------- = 1/13 * 13/3 = 1/3 3/13
Having the extra information about the card changes the probability that it is a King.
A counterintuitive example is testing for a disease. If we know that 1% of people have a disease. The test for the disease is 90% accurate. If you have the test done and it comes back positive what is your chance of having the disease? The intuitive, but wrong, answer is that you have an 90% chance of having the disease. Let’s use Bayes’ Theorem again.
P(Positive Test|Disease) * P(Disease) P(Disease|Positive Test) = -------------------------------------- P(Positive Test)
The tricky part on this one is the P(Positive Test). Of the 1% of people who have the disease it will correctly give a positive result 90% of the time. But, of the 99% who do not have the disease it will incorrectly give a positive result 10% of the time. The resulting formula is:
.9 * .01 P(Disease|PositiveTest) = ------------------------- = 8.33% (.9 * .01) + (.1 * .99)
That means that instead of a 90% chance of having the disease, you really only have an 8.33% chance of having it. In this case knowing the accuracy of the test makes a very big difference in how the test results should be interpreted.
These have wonderful, realistic pictures that move when you turn or move the page. Carol Kaufmann, a writer for National Geographic, writes a crisp descriptive of each image with information about size, habitat, and other interesting information geared to an older than toddler reader.
Polar (6120 words) is owned by ICPL. There are 3 other books in the series, Safari, Jungle, and Ocean that we do not currently own.
My toddler grandson likes his a lot. He usually pulls them out of his book shelf first for reading time. He has many reading times so they are well used. He likes the moving pictures and we grown-ups like the narratives with the pictures. Everyone is well entertained.
Scanimation is a similar photo technology. Peanuts (2550 words) from the comics collection and Waddle (3060 words) from the children’s room are some examples of scanimation books at ICPL. The photos are different from the photicular books and they usually have less text.
Take a look at both, they are fun. These make interesting and cool gifts.
We made a minor change on our website that will be welcomed by many users. Our webmaster has switched the default search in the search box on our website to the catalog. So, if you land on our homepage first and want to search the catalog, you can simply type in your catalog search term, hit return and you will find yourself in our catalog at the results of that search.
Previously, the default search in the search box was for the website itself, and to search the catalog you had to remember to click on “Catalog” after you typed in your search term. Now you are saved from making that click.
This update comes as a result of the public survey of website users that the Information Technology staff did recently. It was the number one comment they got on the survey, and was a change they could make immediately. Watch for other improvements as the IT staff continue to evaluate the survey responses.
Two weeks ago, Brian gave us some very helpful information about registering to vote and researching candidates. Now, we are just one day away from Election Day, and so many people want to know: Where do I vote??? Google has created a very functional Google Doodle to help us find that out.
Go to google.com. Click on the Google Doodle.
¨Let’s have an animal fact a day. Melody posted on Tuesday about “Weird Animal Facts” and right next to it on the new shelf is “The Illustrated Compendium of Amazing Animal Facts” by Maja Safstrom. Well, it was on the shelf until I snatched it up and checked it out. This delightful little book written and illustrated by Safstrom. Every page contains an illustration and one or two or three animal facts. Safstrom’s Instagram shows her flipping through each page.
Here’s today’s amazing animal fact – badgers dig amazing underground dens that can have up to 50 exits (!) and host several badger families. And here an animal fact for tomorrow, (you know you can never ever have too many animal facts, said the reference librarian), a group of flamingos is called a flamboyance. If you want to know more animal facts check out “The Illustrated Compendium of Amazing Animal Facts” or you can call, email or chat or even better visit the Info Desk; we have animal and every other kind of facts at the ready.
Have you recently lost a job or are trying to transition to a new career? The library can help you in a variety of ways to get you back out into the work force. Here are the top ways the library can help you:
Help you find a job opening
Access the Iowa Work Force Development site iowajobs.org at one of our computers near the Information desk on the 2nd floor without a library card or guest pass. With a guest pass or library card, you can access several websites with job postings like Craigslist, Corridor Careers, City of Iowa City Job Openings, Press Citizen, University of Iowa Jobs, or one of the staffing agency websites that post their jobs online (Team Staffing Solutions, Kelly Services, Sedona Staffing Agency, etc.)
If you haven’t visited the Consumer Reports website in the past month, you’ve been missing out on some helpful changes. The website not only has an updated look, it now hosts 360-degree video, an at-a-glance ratings key, and highlights recall notices for products on their ratings page.
Before September, the ratings legend used to use black and red circles to indicate how well a product performed. These symbols weren’t always easy to interpret. Consumer Reports has changed these symbols to make the performance of the product obvious at a glance, using circles, arrows, and colors as in the following illustration:
The 58th U.S. presidential election will take place on Tuesday, November 8, but you know that already, right? I mean, how could you not? History has its eyes on us, but maybe you haven’t decided who you’re going to vote for or maybe you’re not registered. You can register online here. If you’re not sure whether you’re registered to vote in Iowa, you can check that here. You can also register in person at any of the early voting locations, which can be found here. Just be sure to bring along one of these:
- Iowa driver’s license
- Iowa non-operator’s ID card
- Out-of-state driver’s license or non-operator’s ID card
- US passport
- US military ID card
- ID card issued by an employer
- Student ID card issued by an Iowa high school or an Iowa college
The League of Women Voters put together a website so that you can make an informed decision on who to vote for–Vote411. You can enter your address to bring up the races applicable to you and easily compare candidates. The Gazette has an election center as well. If you click on the “Election Guide” and put in your address, it will show you your ballot. The Johnson County Auditor’s website has links to all of the candidates websites here. This is not a moment; it’s the movement. Vote. Don’t throw away your shot–Lin-Manuel won’t stand for it 😉