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Ebooks, the next revolution. But this time is BIG!

Another revolution is about to happen.

A revolution that is many times in size and importance bigger than the music revolution. I call it the e-book revolution.

In this moment a number of technologies are coming together:

On the one side OCR technologies are reaching a level of sophistication, where it is nearly as easy to photocopy a book as to make an ebook out of it. Do you remember when you would go to a photocopy shop, and ask them to make a copy of the book. Now it is that easy to have the ebook version of it, if you know how to do it. This means that more and more books are available in ebook format.

But the difference between the ebooks now, and the mp3, back then, is that when the mp3s came out, a song (5 minutes of fun) was about 5 MB. And since the internet was slower back then, it would take quite some time to download those 5 minutes of fun. Now a book, is often between 1 and 10 Mega Byte. And it can permit you to read it, study it, but also just to consult it.
More about this later.

I thought there were few ebooks around. That mostly you could find some old classics, but nothing really interesting. I was SO wrong.

Here is a collection available for download from pirate bay with more than 1000 ebooks, all on computer science. Here another with practically all of the ebooks from the “* for dummies” collection.

Those are not just some old classics. Those are good new books.

But why are users going through the whole work of digitalizing a single book to post it online? I guess this text will explain us: Continue reading Ebooks, the next revolution. But this time is BIG!

My Sunday Treasure Hunt: Enzymes and Digestion

If you go around the net, looking for information about enzymes and digestion, you often find detailed explanations. Explenations that generally say that enzymes come in a limited quantity, that if you eat raw food you are taking in new enzymes, thus not depleting your resources but if you eat cooked food you deactivate the enzymes, and eventually (over the years) you will have troubles digesting food. If you, instead, go to wikipedia nothing of this is present. Nor if you ask to a ‘normal’ doctor will they tell you any of this. What follows Continue reading My Sunday Treasure Hunt: Enzymes and Digestion

Tag Clouds are hard to Spam

I think the time have come to write my third, and hopefully last contribution to the topic of tagclouds.

I have been hearing a lot of talk on how users should not use too many tags in linking to url. I also am the maintainer of the mindmap maker, and I often look at some of the maps generated (available to everybody). There is a number of people who tend to use an average of between one and two tags per URL. Their maps are often very ordered. No clustering, no hierarchy. (Forgive me if I don’t put a link to such a map, but since I am going to bash this way of using delicious, I’d rather bash a method than a specific human being. Just go to the list of maps and open a couple, odds are one of them will be of the type I am describing). This way of using delicious uses tags as folders, just with the modification that every now and then you can put an URL in more than one folder at the same time. A bit like big bookstore might carry several copies of the same book, and store them in more than one place (and the Tao Te Ching, ends up in New Age -God knows why- and in Religion).

Of course tags tend not to fit exactly. My Tag Clouds and Cultural Change will be under Tags or Folksonomy or Sociology… Whatever you chose you probably will not put it under Ajax. And yet most of the analysis was done studying the spreading of the term Ajax.

Let’s make a few simple calculations. Continue reading Tag Clouds are hard to Spam

Tagclouds and cultural changes

In the previous post I discussed how we can measure the relative importance of tags in a post, by calculating their weight, as

  • weight of tag t= (number of people using t)/(total number of people)

I also said that:

Not only we could study a culture by studying the differences in the power law approximated by the tag clouds used by people of that culture. But we could even measure cultural eartquake by measuring the difference between the tag cloud being generated before a certain event, or after a certain event.

Independently Clay Shirky was coming at a similar conclusion, although he more focused on temporal changes that seem more signature of a particular subgroup of people all bookmarking a site at a certain time:

During a period of about 120 users’ additions of OIO, 20 or of them used the tag ‘ia’, putting it between #7 and #10 during that period. Now it is down to #17. This suggests that one or a few IA-oriented sites or mailing lists posted the link, and it got a flurry of attention from those taggers in a narrower window of time. This in turn suggests a conversationally tightly-knit IA community.

Through this tool we can see changes in the culture we are living in. We are used to feel those changes, but generally we never were able to measure them. Maybe now we might start to be able to do it.

But let’s go back to the tag weight. Terrell Russell took the ball, and in one evening of programming presented a tool to actually see how the weights change in time.

Nothing to say about the tool. It works perfectly well, and although it can be enhanced in many little ways, it already is very useful. Not bad for one evening.

More interesting, from my point of view, is how, through this tool we can see changes in the culture we are living in. We are used to feel those changes, but generally we never were able to measure them. Maybe now we might start to be able to do it.

No change

Tag Clouds rapidly converging

First of all I would like to show you the graph of a part of the culture where no changes are happening:
From the site: Nifty Corners. 1859 people having bookmarked it by now. The values soon converge to what we can expect to be their definite value (for the culture we are in).

Little Social-Quake

Continue reading Tagclouds and cultural changes

On Tag Clouds, Metric, Tag Sets and Power Laws

Note: This entry is connected also to a mindmap. Some people were having problems in opening the page because of that. As such the mindmap has been stored in a separate page, and can be viewed from here.

Introduction

As correctly pointed out by Jeffrey Zeldman tag clouds are becoming more and more popular. Yet I keep seeing services which should be using tag clouds that keep on using tag sets. It is not just a problem of programming a tool which can only support tag sets, but also but also of programming tools which might in principles produce tag clouds, but such that the users are not invited to use a tag if one already exists, and as such don’t generate a tag cloud.

Example of the first type of tools are Flickr, 43things, consuMating, tagsurf * , example of the second is the tagged version of the BBC* . In all those cases a tag set is used, where instead a tag cloud would be more appropriate. Some of the differences between a tag cloud and a tag set where explained in Vanderwal.net: Explaining and Showing Broad and Narrow Folksonomies. Let’s see them again, and see some consequences of those differences, which should clarify when is better to use one tool and when is better to use the other. Continue reading On Tag Clouds, Metric, Tag Sets and Power Laws

A house divided

As the price of houses rises, more and more people find that the best solution is to divide a house among friends. Usually each person gets a room. The problem then is: who gets what room and how much should he pay. Usually the total rent is fixed, and usually the rooms are not exactly all the same. Some might be bigger, some smaller. Some might have a better view, more privacy, closeness to the toilet, more silence, and so on. And what’s also important is that different people might value the various elements in different ways.

I present here two ways of splitting the rent and dividing a house. I personally favour (and has designed) the second, but while I was presenting this method to some friends to get some
feedback, I was told the other, it seemed simpler, yet interesting enough to add it. They both assume that:
a) the rent is fixed,
b) there are no favoritism among the will-be-housemate on
who gets to choose first.

The ‘find the objective value first’ method.

Before the rooms are assigned, get together and agree on what are the objective value of each room (i.e. 20% of the rent for this, 50% of the rent for this). The total value must of course be the whole rent. Then randomly select who gets what room (at the agreed price), and as a final action people are allowed to exchange rooms if they want to.
Positive element: it is simple and quite straightforward.
Negative element: it assumes that people can easily agree on the actual relative value of the rooms, and that such value does not change respectively to the persons.

The ‘each person gets the best room’ method.

As I said this is the method that I love most. First of all let each person inspect all the room. Then each person, writes, secretly, the relative value of each room in a piece of paper. The sum of the values must be equal to the requested rent. The idea is to divide the house so that each person gets a room, and pays for that room the value THEY wrote on the piece of paper, while the sum of the valued paid by each person totally covers the requested rent.

Obviously, very often, the collected money would then be higher than the rent. Let’s call the collected money minus the monthly rent, the ‘extra money’.

Often there is more than one solution, that permit to have a some extra money each month. When this happens, the solution that permits to maximize the extra money is chosen. The extra money is then used to pay for the light, any extra expenses, or whatever is needed for the house.

Sometimes there are more than one optimal solution, that is some solutions generate the same extra money, everybody is paying the requested cost for each room, and all other solutions are less optimal. In that case the adopted solution will be one of the optimal one, randomly chosen.

Examples, examples:
Let’s suppose we have a house with 3 rooms (a, b, and c) and 3 persons (A, B, and C). Let’s suppose the total rent being 100.

Person A might find the three rooms equivalent, so he might just write (a: 33.3, b: 33.3, c: 33.3). Person B might instead favour room B, because is more sunny, and she likes to paint, and then she thinks that room ‘a’ is slightly better than room ‘c’, infact she would prefer not to be in room c at all, so she would write: (a: 35, b: 40, c: 25). Person C instead does not care about the sun, but has noticed that room A has more privacy, plus is near the toilet, and since he likes to have his gf as a guest, thinks that having room A would be a better deal. So he votes (a: 40, b: 30, c: 30).

Then the papers are revealed.

Generally when a room has a person that values it more than all the others, and he values that room more than all other ooms, then that room gets taken by that person at the price he has choose.

In our example we have:
A: (a: 33.3, b: 33.3, c: 33.3)
B: (a: 35, b: 40, c: 25)
C: (a: 40, b: 30, c: 30)
which would give us that A would get room ‘c’ paying one third of the rent. B would get room ‘b’ paying 40% of the rent, and C would get room ‘a’ for 40% of the rent… and the collected money each month would be 33.3+40+40=113.3 . The extra money would be 113.3-100=13.3 and would be used to pay for the electricity, water, gas, or whatever.

It is also possible to rinormalise the prices, by lowering them so that the total sum becomes exactly the cost of the rent, while the relative ratio remains the same. In our example
A: (33.3/113.3)*100=29.4
B: (40/113.3)*100=35.3
C: (40/113.3)*100=35.3
and person A would pay 29.4 of the rent (since he took the room nobody wanted)
person B would pay 35.3 of the rent (and took the sunny room)
person C would pays 35.3 of the rent (and took the room with more privacy)

So, what if the situation is not that easy. There isn’t a person that prefers each room? For example you could be in a situation like:
A: (a: 45, b: 45, c: 10)
B: (a: 40, b: 40, c: 20)
C: (a: 40, b: 30, c: 30)
well in this case it is obvious that person A will get either room a or room b. But it is also obvious that room c will go to person C. So C get’s c at 30% of the rent. Both A and B value the room a and b equivalently. But once the room will be assigned person A will pay more than person B, so it seem fair to me that person A chooses a or b and pays 45, and person B gets the remaining room, but pays less (40).

But things can get even more complicated if some people
value some rooms exactly the same:
A: (a: 45, b: 45, c: 10)
B: (a: 45, b: 45, c: 10)
C: (a: 40, b: 40, c: 20)
in which case A and B have obviously to randomly choose who gets what.

Or if the situation is symmethric among the rooms:
A: (a: 40, b: 30, c: 40)
B: (a: 40, b: 40, c: 30)
C: (a: 30, b: 40, c: 40)
In which case you randomly choose if A gets a or c, and then the other follow obviously.

So here we have the first mehtod, where everybody chooses the value together, this is equivalent on the second method if everybody agrees on the relative value:
A: (a: 35, b: 40, c: 25)
B: (a: 35, b: 40, c: 25)
C: (a: 35, b: 40, c: 25)
After which, also in this method, you would randomly pick who gets which room.

Please, let me know if you have tried it and if it was succesful.