# Probability/ Stats Puzzle – 3

I encountered another problem in the same book (I will disclose the name of the book in a later post along with the answer). Here is the problem:

Two contestants have reached the last round of a TV quiz contest and one of them is hoping to be the winner of a prize of 10 mn (currency deliberately left vague) via a tie-breaker. Even after the tie-breaker, neither of them has beaten the other.

The show-host offers to break the tie with a coin (my guess is that the show host did not have any more questions left :-)). However, to maintain the suspense and gain more TRP, he proposes that the winner will be one who reaches six (6) correct calls first.

After 8 flips, contestant A has 5 correct calls, and contestant B has 3 correct calls. At this stage both the contestants agree NOT to continue with the flipping of the coin (maybe the coin is lost or it breaks or falls into something disgusting – use your imagination). They have to decide on the winner based on result of the 8 flips.

Here are some proposals:

1. Contestant A says that since he is leading, he should get the 10mn.
2. Contestant B says that since the flipping was called off before the final result, the 10mn should be shared equally.
3. The show-host says that TV quiz program sponsors should retain the 10mn, since both the contestants agreed to call off the contest.
4. Someone from the audience suggests that the prize money be split in the 5:3 ratio (5 for A and 3 for B), in line with the number of right calls
5. A mathematician calls in to suggest that the money be split A7:B1 (try and guess the logic here, it is related to the probability of winning from this point, if the flipping had continued)
6. Any other…

It is interesting to note so many options to a simple situation.

Please share your suggestions in the “comments” feature available below.

# Probability/ Stats Puzzle – 2

I encountered this simple problem in a book (I will disclose the name of the book in a later post along with the answer).

Here is the problem:

You need to call the throw of a dice a 1000 times. Like all dices, in each throw, this dice also gives you a number between 1 and 6. You are also told that the dice is slightly distorted / damaged – the probability of getting the six results is as follows: 1- 20%; 2- 10%; 3- 25%; 4-15%; 5-15%; 6-15%.

What strategy would you use to call the answers for the 1000 throws? Your objective is to get the right answer for a maximum of the throws.

Here are some answers that I have heard:

1. Call the number ‘3’ all the 1000 times – this is the most common answer I have heard.
2. Call the numbers in the same pattern as the probability: 1- 200 times; 2- 100 times; 3- 250 times; 4-150 times; 5-150 times; 6-150 times.
3. Call the numbers randomly, ignoring the distortion in the dice.
4. A variation of 2 above is to call the numbers in the same pattern, but also taking into account the answers to the past throws, so that we try and keep the probabilities similar to the expected patterns. So if in the first 100 throws, 1 has already rolled more than 20% and 2 has been rolled less than 10%, then in the 101st throw, call 2 instead of 1, and so on.
5. There are other possible answers too – and the right one may not be listed above (this is not a mutiple choice question 🙂 )

Work out the reasons for your choice, not just make a choice. The reasons are more important.

This is a simple question, and you should get the right answer.

The answer will be posted later.

Please share your views in the “comments” feature available.

# Book Review – “Made To Stick” by Chip Heath and Dan Heath

The messages from this book have ‘stuck’ to me over seven years. I remember this book very well and have been implicitly and explicitly guided by concepts that I learnt when I read the book long ago.

The authors have managed to implement what they are trying to teach :-)!

The full title of the book Made to Stick: Why Some Ideas Take Hold and Others Come Unstuck – makes the intent of the authors very clear. It is about conveying ideas and messages more effectively to achieve whatever you are trying to achieve Anyway, here is a passage from the Introduction of the book:

“We wrote this book to help you make your ideas stick. By ‘stick’, we mean that your ideas are understood and remembered, and have a lasting impact – they change your audience’s opinions and behavior.”

— Introduction: What Sticks? – Made to Stick

## Details of Made to Stick

Made to Stick: Why Some Ideas Take Hold and Others Come Unstuck

Authors: Chip Heath and Dan Heath

Publishing Date: 2007

Publisher: Arrow Books

Formats Available In: Hardcover, Paperback, Kindle, Audio

Available at: Amazon.com, Amazon.in.
This book is an entertaining, practical guide to effective communication. Extremely well-written, it uses the principles that are proposed in the book for effectively making ideas stick with the audience. It continues with the idea of ‘stickiness’ earlier popularized by Malcolm Gladwell in his book The Tipping Point.

The book contains a number of examples, cases, urban legends, personal stories, and analysis that are used to support the principles of effective communication proposed by the authors. The “Clinic” in each Chapter is used to illustrate the application of the principles discussed to a specific case study or idea.

According to the book, there are six principles of effective communication that combine to form the acronym SUCCES (the last S from “success” is absent). These six principles are:

• Simplicity. Strip an idea to its core. Keep prioritizing the ideas till you have something simple and profound.
• Unexpectedness. Use surprise to grab the audience’s attention.
• Concreteness. Avoid the abstract. Avoid ambiguity. Use vivid images.
• Credibility. Use whatever will make people believe in the idea. This could be the ‘messenger’ or the way the message is conveyed. (“For instance, if you have the security contract for Fort Knox, you are in the running for any security contract“)
• Emotional. Form an association between something they do care about to connect to things they don’t yet care about. (The most frequent reason for unsuccessful advertising is advertisers who are so full of their own accomplishments – ‘the world’s best seed!’ – that they forget to tell us why we should buy it  – ‘to have the world’s best lawn!‘)
• Stories. People remember stories compared to abstract messages. (For example, Subway used the story of a man who lost a lot of weight while eating their diet sandwich instead of providing data on calories and fat content of the sandwich).

There are over a hundred examples of successful messaging to illustrate each of the six principles. The book is extremely easy to read and difficult to put down once you start.

I strongly recommend at least one read of the book to following professionals – they can keep the principles in mind while crafting messages and campaigns:

• Executive management
• Marketing/ sales folks
• HR Policy makers
• Consultants/ Trainers
• People trying to handle change management

The book is available in multiple formats at Amazon.com, Amazon.in.

## About the authors

Chip Heath is a Professor of Organizational Behavior in the Graduate School of Business at Stanford University. His research examines why certain ideas – ranging from urban legends to folk medical cures, from Chicken Soup for the Soul stories to business strategy myths – survive and prosper in the social marketplace of ideas.

Dan Heath is a Senior Fellow at Duke University’s CASE center, which supports entrepreneurs who are fighting for social good.

Chip and Dan Heath have jointly co-authored another book Switch: How to change things when change is hard.

You can also view this 4:44 min video where the authors Chip and Dan Heath are being interviewed (uploaded on youtube):

If the clip does not load click here http://www.youtube.com/watch?v=2zlld9TA-Vg

The book is available at: Amazon.com, Amazon.in.

## Quick Quiz

In the two you tube clips below, can you figure out which of the principles of SUCCES are most prominently used?

Clip-1: Series of “You Don’t Mess With Texas” ads used to address littering in the state of Texas with celebrities conveying the message

If the clip does not load, use http://www.youtube.com/watch?v=hYp1gc5joQg&list=PLilaP-sCTPd2aCHcVHdnNpNT7AXXKXxO5

Clip-2: A “Belt Up” ad that won a lot of awards

If the clip does not load, use http://www.youtube.com/watch?v=bZ2EKswyTao

Please use the comment feature below to send in your responses.

Please feel free to share your views, experiences or queries, using the “comments” feature available.

Notes:

Nothing Official About It! – The views presented above are in no manner reflective of the official views of any organization, community, group, institute, or association. They may not even be the official views of the author of this post :-).

# Henlon’s Razor: Sound Principle for Processing Interpersonal Interactions

Here is the statement, attributed to Robert J. Henlon:

• `"Never attribute to malice that which is adequately explained by stupidity".`

Though the origin is not too clear, there are others who have been credited with similar statements/ quotes. Here are a few of them.

Science Fiction author Robert A. Heinlein in his short story Logic of Empire:

• “You have attributed conditions to villainy that simply result from stupidity”

Johann Wolfgang von Goethe in The Sorrows of Young Werther:

• “…misunderstandings and neglect create more confusion in this world than trickery and malice. At any rate, the last two are certainly much less frequent.”

Jane West’s The Loyalists states something similar in a more sincere (less cynical/ insulting) manner:

• “Let us not attribute to malice and cruelty what may be referred to less criminal motives. Do we not often afflict others undesignedly, and, from mere carelessness, neglect to relieve distress?”

All of the above can be applied to actions, situations, and interactions that cause inconvenience, hurt and pain, for many reasons:

1. It is possible that there was no malice, deliberate intention, or evil motives for the action/ inaction by the other party. Maybe it truly was carelessness, incompetence, or stupidity.
2. It is easier to emotionally cope up with consequences of the action/ inaction if you do not think that it was the result of malice (whether or not it is true).
3. When your action / inaction is inconvenient/ hurtful, it may be preferable (for you) to have others attribute it carelessness, incompetence, or stupidity (though some people may prefer being known as ‘evil’ rather than ‘incompetent’ 🙂 ). If so, it is preferable that everyone uses the same principle.

People often attribute deliberate malafide intent on the powerful (Executive Management, Human Resources) within the organization. The same holds true for the way journalists analyze governments. Most of these powerful people are clueless themselves. It may therefore helpful to remember that:

• “Cock-up theories”  are more likely to explain man-made problems than conspiracy theories.
[This also means ‘luck and randomness is more likely to explain success than thought-out strategy’]

You many also want to read Occam’s Razor for Design of Systems and Processes.

Please feel free to share your views, experiences, and queries, using the “comments” feature available.
You may also forward the link to this post to your friends, colleagues, and anyone else who may be interested.

Notes:

Nothing Official About It! – The views presented above are in no manner reflective of the official views of any organization, community, group, institute, country, government, or association. They may not even be the official views of the author of this post :-).

# Are Surveys Really Objective?

If you are under the impression that you should believe the results of surveys (customer satisfaction, employee satisfaction, etc.), you may want to rethink after you have a look at this episode of  Yes, Prime Minister (Episode “The Ministerial Broadcast”). Sir Humphreys instructs Bernard on how to design and administer a survey to get the result that you want. See this youtube clip (the quaint accent in which they speak English alone is worth it 😉 )

If your youtube clip does not load, click here: http://www.youtube.com/watch?v=G0ZZJXw4MTA

Please feel free to to share your views, experiences, and queries, using the “comments” feature available.
You may also forward the link to this post to your friends, colleagues, and anyone else who may be interested.

Notes:

Nothing Official About It! – The views presented above are in no manner reflective of the official views of any organization, community, group, institute, country, government, or association. They may not even be the official views of the author of this post .

# Occam’s Razor for Design of Systems and Processes

Occam’s (or Ockham’s) razor is a principle attributed to the 14th century logician and Franciscan friar William of Ockham (does this profession  still exist? I am yet to meet a “logician” :-)).

Occam’s razor states that “one should minimize the assumptions to the minimum necessary to solve any problem”. It is a minimalistic principle (often called principle of parsimony) and can be used as a heuristic while doing scientific modelling and building theories.

Though the principle has been found in the writings of earlier medieval philosophers, William of Occam has been credited with it because he was its most prolific proponent.

Occam is attributed to have said something like “Numquam ponenda est pluralitas sine necessitate” (as expected, he did not say these things in any modern language :-))- which means “plurality must never be posited without necessity” [if this was how people promoting simplicity spoke, I really don’t want to know how others spoke]

Various versions/ derivations of the Occam’s razor include:

“Keep it Simple, Stupid”

“Simpler explanations are, other things being equal, generally better than more complex ones”

“Simpler hypotheses are generally better than the complex ones”

“Everything should be kept as simple as possible, but no simpler.” (Einstein?)

One of the common misuses of Occam’s razor is perpetrated by woo-scientists who say that God / brahman/ mystical forces are simpler explanations for any phenomenon that is difficult to explain. You can know more about woo science here and here.

Though Occam’s razor was initially applied to “explain things”, it can equally be applied to “building things” like systems and processes. Consciously using Occam’s Razor may make these systems easier to operate, maintain and upgrade.

Here are new variants of Occam’s razor as applied to design of systems and processes:

“It is vain to do with more what can be done with fewer”

“A simpler design that achieves the purpose is better than a more complex design”

“Minimize the entities in any design to make it effective”

“Simplicity is the ultimate sophistication” (da Vinci?)

Here is a write-up on how Occam’s razor has been used in Web Design “Occam’s Razor: A Great Principle for Designers“.

And another delightful article on design principles is “12 Laws and Principles to Aid You in Your Design” – Occam’s razor is number 1 in this list.

See this Wikipedia page for more details on Occam’s razor.

Occam’s razor has also been applied to human interactions, and that is the subject for another post, but here is a teaser:

• `"Never attribute to malice that which is adequately explained by stupidity".`

Please feel free to share your views, experiences, and queries, using the “comments” feature available.
You may also forward the link to this post to your friends, colleagues, and anyone else who may be interested.

Notes:

Nothing Official About It! – The views presented above are in no manner reflective of the official views of any organization, community, group, institute, country, government, or association. They may not even be the official views of the author of this post :-).

# Probability/ Stats Puzzle – 1 (Solution)

If you have not tried to solve the puzzle, click here for the problem. The problem was discussed in an earlier post.

This is a famous puzzle, called the “Monty Hall Problem”. Monty Hall was a host in the early episodes of the game show Let’s Make a Deal.

The common version of the the puzzle used three doors (instead of 3 boxes) and a car and two goats (instead of gold and garbage).

The problem was originally posed by Steve Selvin and became famous when it was quoted by Marilyn vos Savant in Parade magazine in 1990.

The answer: You increase the probability of winning the gold if you change your choice of the box to open. The probability of winning the gold is only 1/3 if you continue with your original choice and 2/3 if you change your choice.

Here is a brief explanation of why:

When you initially selected a box, you had a 1/3 probability of being right. The host knowingly opened a box with garbage in it, so that eliminated one of the wrong choices.  You still have a 1/3 probability that you initially chose the right box; this means that the other unopened box has a 2/3 probability of containing the gold.

Amit Bhattacharjee, Satish K Mariyappagoudar, and Patrick OToole got it right.

Better explanations are provided on the wikipedia page here.

Or you can watch the youtube video.

If the video does not load, the link is http://www.youtube.com/watch?v=mhlc7peGlGg.

You can also search the internet for the keywords “Monty Hall Problem” – you will get lots of hits.

Please feel free to to share your views, experiences, and queries, using the “comments” feature available.
You may also forward the link to this post to your friends, colleagues, and anyone else who may be interested.

Notes:

Nothing Official About It! – The views presented above are in no manner reflective of the official views of any organization, community, group, institute, country, government, or association. They may not even be the official views of the author of this post :-).

# Probability/ Stats Puzzle – 1

This problem was presented to me by Swapna (my wife) on last Friday – I could not work out the right answer even after considerable struggle.

You are participating in a TV show contest. You have reached the last round. If you win this round, you get take home a pure gold brick of 5 KG (5KG = 11.02 lbs); if you lose you have to take away an equivalent quantity of stinking garbage.

Here is the problem in the last round:

There are 3 closed boxes (let us say B1, B2, B3). Inside two of the boxes is garbage. Inside one of the boxes is the gold. You have to open one box and take home whatever is in that box. You decide to open B1. The show-host/ quiz-master asks you to stop, and as a hint opens one of the other two boxes, and inside that box there is garbage. The show-host gives you the option of changing your choice. Would you still go for your original choice or switch to the other unopened box?

Here are some relevant assumptions/ hints/ guidances:

1. Most important: you would prefer to take home the gold instead of the garbage :-).
2. You will not be able to smell the garbage or gold without opening the boxes, or in any way be able to “know” what is inside the unopened boxes.
3. You do not know the show host’s motivation. The show-host may be trying to help you or trick you, or trying to increase hir (his/her) popularity rating, or just following a script. So, do not consider the show host’s motivation in trying to solve the problem (when Swapna presented me the problem, I went on the motivation track, and could not approach it as a problem of probability, even after she told me to ignore the show host’s motivation 🙁 ).
4. There is no “trick” in the problem or the solution – so, approach it as a problem of probability/ statistics.
5. Do not be lazy and search the internet to find a solution. That is cheating. I have changed some things in the problem so that is not easy to search. However, this is not a test of how quickly and ingeniously you can search the internet.
6. You will have to work out the reasons for your choice, not just make a choice. The reasons are more important.

Don’t feel bad if you don’t get the answer right, many renowned statisticians have got it wrong.

The answer is available in another post here.

Please share your views in the “comments” feature available.

# Book Review – “The Paradox of Choice” by Barry Schwartz

I had read this book around four years ago, and had liked it. So posting a review of the book on this blog has been on my list for a while now.

The full title of the book The Paradox of Choice: Why More is Less (How the Culture of Abundance Robs Us of Satisfaction) makes the author’s thesis / proposal pretty clear. Anyway, here is a passage from the book that contains the key theme:

“Freedom and autonomy are critical to our well-being, and choice is critical to freedom and autonomy. Nonetheless, though modern Americans have more choice than any group of people ever has before, and thus, presumably, more freedom and autonomy, we don’t seem to be benefitting from it psychologically.”

Chapter 5- The Paradox of Choice

This engagingly written, semi-academic book on consumer psychology brings in new insights into impact of excessive choices available to consumers in terms of speed of decision making (and whether a decision is made at all), and the statisfaction with the decision after it is made. The book also looks at two types of people – the ‘maximizers’ and the ‘satisficers’ in the context of decision making (when faced with many choices).

The gist is as follows:

• The universal assumption that more choice is always better is not correct.
• When people are given too many choices, they get paralyzed and often don’t make any decision. Shwartz quotes multiple studies to support his theory.
[One such example: At a luxury food store, researchers set up a table offering samples of jam. Sometimes, there were six different flavors to choose from. At other times, there were 24. People could taste the jam before they purchased it. The sales when there were six flavours to choose from were singnificantly higher than when there were 24 flavours (subsequently there have been doubts expressed on the design of the experiment, sampling and possibility of random variation and other factors that may explain the difference)]
• When we make a decision after evaluating many choices, we are more likely to be unhappy/ anxious about our decision, than if we had fewer choices to evaluate.
[Example: Students from a photography course were allowed to keep one of their prints. Half of the students were later allowed to change the print they had earlier selected, the other half were not given such a choice. Even though very few of the students who were permitted a trade actually exchanged the print they had had earlier selected, the group that was not given an option to trade was happier with their print than the group that was given a second choice]
• Decison making is a stressfull process, and when there are too many choices, the stress and anxiety levels increase (reviewer’s note: maybe that is why pre-plated meals are so popular!), during the decision making process and after it.
• There are two types people – the ‘maximizers’ and the ‘satisficers’.
• Maximizers try to take the best decision, and they try to make sure that they have evaluated all possible options. Maximizers tend to be slow in decision making and are more anxious about their choice even after the decison is made.
• Satisficers make their decision as soon as they find an option that is satisfactory and stop looking at other choices. They normally do not keep validating that their decision was the right one. They are less stressed during and after their decision making.
• Shwartz also provides some practical steps to derive more satisfaction from the choices that we make.

The book presents a new way of looking at decision making. Though availability of choices is empowering to the decision maker, too many choices are paralyzing, time-consuming, stressful, and eventually disatisfying. Excessive choices is a phenomenon of the developed nations in the West and this phenomenon is slowly spreading to all parts of the world. Shwatrz makes a plea to increase the choices for ‘have nots’ and reduce them for the ‘haves’, so that everyone is happier. The book does not say how to determine the right number of choices.

The book is written in a mix of academic and racy/ popular styles. Also, many of the concepts are repeated with multiple examples. In spite of that the book is engrossing and engaging.

I strongly recommend at least one read of the book to following professionals – they can keep the principles in mind while providing choices to their managers, staff, and customers:

• Product and service designers
• Process designers
• HR Policy makers
• Marketing/ Sales folk

The book is available in multiple formats (you have to make a decision :-)!) at Amazon.com, Amazon.in. The book should be equally readable in all the formats – I read the paperback format.

About the author

Barry Schwartz is the Dorwin Cartwright Professor of Social Theory and Social Action at Swarthmore College. In addition to the Paradox of Choice, he has authored/ co-authored many other books like Psychology of Learning and Behavior and The Costs of Living. He frequently publishes editorials in the New York Times applying his research in psychology to current events.

Here are some details, if you want to get a copy of the book:

Author: Barry Schwartz

Publishing Date: 2004

Publisher: Harper Perennial

Formats Available In: Hardcover, Paperback, Kindle, Audio

Available at: Amazon.com, Amazon.in.

You can also view this 20 min video where the author Barry Schwartz explains the concepts in the book in his TED talk (uploaded on youtube):

## The book is available at: Amazon.com, Amazon.in.

Please feel free to share your views, experiences or queries, using the “comments” feature available.

Notes:

Nothing Official About It! – The views presented above are in no manner reflective of the official views of any organization, community, group, institute, or association. They may not even be the official views of the author of this post :-).

# You don’t need a Kindle device to read a Kindle ebook

Till a few months ago I had not registered the fact that I could read ebooks on other devices (like my laptop) and didn’t need a Kindle device. This was in spite of my wife’s constantly telling me so for years.

Last month, though, the coin dropped and I took aside an hour to set up my laptop to read Kindle ebooks. Then I felt that it may be worthwhile to have a blog entry on this topic because I suspect there may be a few (or many?) others like me who dismiss the very idea of reading Kindle ebooks because they don’t have a Kindle device. So I invited my wife, Swapna Kishore, to write this post for AlignMentor

[Brief intro: Swapna Kishore is an author of technical books and speculative fiction. She also maintains a comprehensive website to support dementia daregivers in India. She blogs here.

Over to Swapna…

## Read Kindle ebooks within minutes on your laptop, mobile, or tablet – by Swapna Kishore

The world of instant information is just a few keystrokes away now because we can buy and start reading ebooks within minutes –  the latest books from across the world. Amazon, for example, has a vast number of ebooks in its Kindle store.

But wait…are you availing this opportunity? Or have you brushed it aside saying, “I don’t have a Kindle (device).”

Because, you see, you don’t need a Kindle device to read a Kindle ebook. You can read Kindle ebooks on your laptop, mobile, tablet, or even in your browser. It takes just a few minutes enable any of these devices to read Kindle eBooks. Really.

A quick way to understand this is

• A Kindle e-reader is a physical device that you can hold in your hands. You can use it to read documents in a number of formats. You can read Kindle ebooks. You can also read other stuff (PDF files, DOC files, etc., depending on which Kindle e-reader you have). You can also do other tasks, but that’s irrelevant for our discussion.
• A Kindle book (ebook) is an electronic counterpart of a book. It is the digital version of the book, a file using a particular format. You can read this file on any device that can interpret the format and display the content (the book). A Kindle ebook can be read on the Kindle e-reader device.  And if you install the appropriate Kindle Reader App (software) on another device, a Kindle book can also be read on that device.

So, if you want to read a Kindle ebook on your laptop, it’s easy – install the app for your version of Windows or Mac, and then use it to read ebooks. The process is the same for other devices; Kindle ebooks can be read on your laptop, smartphone, iPad or Android device, or even your browser.  What’s more, you can read the same book on multiple devices. Read it on your laptop. Then, if you are in the car (and someone else is driving it) and you want to continue, you can resume the reading on your iPad or iPhone or Blackberry. You can even synchronize to pick up reading at the point you left it. It’s that simple.

The download links and procedures for the required apps are available at the Amazon site. So all you need to do is:

• Decide which device(s) you want to read your ebook on (your iPad? your Android device? your laptop? one device? more devices?)
• For each device, download and install the relevant free Kindle reading app. Apps are free, and downloadable from Amazon (for Kindle ebooks). Check the Kindle section on Amazon for “Free Reading Apps”(currently here.)
• Test it out:
• Buy a Kindle ebook and make it available on the device(s) you want to read it on (using wireless or download and USB transfer). For testing the app, you can “buy” a free ebook: Check for Kindle ebooks, using Sort –> Price Low to High
• Start the “Kindle reader” on that device and read the book

Now that your device(s) is set up to read Kindle ebooks, next time you can just buy the ebook, deliver/ download it to the device, and start reading. You can also read a sample of a Kindle book before you buy it. Every Kindle ebook is just a few clicks (and a few rupees/ dollars) away.

I have been using my laptop to read Kindle ebooks for over two years. In fact, I read ebooks from all ebook vendors on my laptop (they all have ways for you to read their ebooks on multiple devices). I bought a Kindle e-reader some months ago, and I use that sometimes, but even now, I often read ebooks on my laptop. (I can check my email and Facebook on the side, see 🙂 Or even draft a blog post like this one 🙂

And now, just in case you didn’t feel like reading the above:

Please feel free to share your views, experiences or queries, using the “comments” feature available at the top of this article/ post.

By the way, if all this has made you feel that you need to seriously consider a Kindle device, then click here.

Notes:

Nothing Official About It! – The views presented above are in no manner reflective of the official views of any organization, community, group, institute, or association. They may not even be the official views of the author :-).

Book reviews uploaded on the same blog: