Your Conception of What is Right to Seek

Point 5:

If you are convinced or persuaded by the author that the ends he proposes are worthy, and if you are further convinced or persuaded that the means he recommends are likely to achieve these ends, then it is hard to see how you can refuse to act in the way the author wishes you to.

This section of Mortimer Adler's chapter on How to Read a Practical Book is about how the
 15 Rules for Analytical Reading (pdf)  can be applied to reading a Practical Book.  A Practical Book is one which deals with how men can do better or worse, and it recommends a course which the author thinks is better.  So the reading does not end with simple knowledge, but with an implied directive to DO something as a result of the knowledge.  

The first step in reading is analysis.   You ask:
What is the book about?  Can you sum up the "thesis" or main idea in a short sentence?  How do its parts contribute to the whole?  What problem is the author trying to solve?
For a practical book, this step doesn't change much.   Since a practical book is recommending a course of action for you, the reader, you would add the question:

What does the author recommend that I do?

The second step in reading is interpretation.   You ask:  What are the "key words", the specific vocabulary the author uses?  What are his main propositions?   What are the arguments (that is, the chain of reasoning to support what he says?) .  How does he solve the problem that the book is about?
Again, this doesn't change much for a Practical Book.    For the last question, you would rephrase it --  

What steps does the author recommend for you to solve your problem or work towards the goal stated in the book?

The third step in reading is evaluating truth.   Is the book true?   This requires outside knowledge, either from other books or from real world experience, and fair judgment.   In order to disagree with the author, especially in public, you are obligated to understand what he is saying; furthermore, you need to use courtesy and restraint; you also are obligated to present evidence that supports your claim.
This changes somewhat in reading a Practical Book.   Adler says:

The main consideration is whether the author's objectives -- that is, the ends he seeks, together with the means he proposes to reach them -- accord with your conception of what it is right to seek, and of what is the best way of seeking it. 

You would ask something like:  

Is this a worthy end, and are the means he proposes workable?

The fourth step in reading is determining significance.  You ask:  What of it?  Given that this is true, what are the implications?  What does this change in my thinking?

This is the step that changes most of all in reading Practical Books.   It is expressed above in Point 5.   Practical Books require action to complete their intention, so if you agree with the goals and with the means to achieve them, then reasonably you will act accordingly.  So you would ask:

Given that I agree that the end is worthy and the means he proposes are doable, what will I then do differently as a result?

There are some exceptions to this, I would think
(these are ones that come to my mind, not ones that are listed in the book. Adler, I would think, would classify these as "psychological reasons" -- ie, reasons that are to do with the reader per se, not the book per se)

1. The problem isn't one that you have, at least not at the moment -- for example, you are reading a parenting book but you don't have any kids. Or you are reading about politics or economics in a different country.  Basically you are reading a practical book for only very remotely practical reasons -- perhaps to clarify your thinking and apply the solutions by analogy to ones that you are closer to.
2. The steps taken to achieve the goal ARE, or SEEM to be, out of your reach.  You want to exercise but you can't seem to find the time; or you want to change your parenting practices but your spouse is unsupportive.
3. Your instincts are ringing warning bells.   This happens when something SOUNDS plausible but you can't bring yourself to buy it.   You might not discard the ideas wholesale but you aren't inclined to take big risks to follow something you can't completely get on board with.   Honestly, I've learned to trust these yellow alerts at least provisionally, and hold off until I have more information.
4. It's not high enough on your priority list to justify the work required Since practical judgment is basically about prioritizing relative goods, you might agree with a book about the value of post-graduate education yet, because you have four small children, believe that other things come first for you.  Or perhaps you'd like to be perfectly fit but because you have a busy life educating high-schoolers you settle for basic cardiovascular fitness levels. 

This is the end of the self-tutorial!   I want to use it to steer my way through some of the books I have been reading but we'll see.  Anyway, having it laid out bit by bit will hopefully help me and if it helps anyone else at all that is a bonus!