OU - M359 - A result, sort of.

Well, there we have it. The results for the first presentation of M359 are out. And they are disappointing as expected. TMA wise I was at distinction level although I knew that there was no way that I would achieve the marks needed in the exam to sustain that. However, as documented elsewhere, the exam was a real pigs-ear (and I speak as a vegetarian - I have nothing against pigs-ears per se). The questions were vague, three of the questions required constant referral to some tables that had been added as an appendix - which meant that it was not possible to read the questions and view the tables at the same time - the constant flapping of papers reminded me of a flock of seagulls alarmed by a marauding dog on the beach (but with out the piercing screech - which I tried to keep to a minimum so that I didn't disturb the MSc students in the next row).

All the course text need re-writing into English (I wonder it would score on the blog-readability test).

And I feel fed-up that I am forced into criticizing the OU - because I think that it is a fantastic institution.

Still, a pass is a pass is a pass. No resit required. Phew!

OU - M359 - One final errata

I didn't really expect to be commenting on an errata for M359 - mainly because the course finished back in October. But, as was the case many times during the course, an errata has been issued - and without explanation!

The website has been stating that the exam results will be available by 14th December. And now, on the 13th December, this has suddenly changed to 21st December! Okay, no big deal for me - its not as if they have told me that I have failed (for that will surely come later), but I know of one other student who needed to know the result on the 14th because it greatly influenced what they did next.

So one wonders why the M359 results have been delayed - many other courses have had their results released on time - you only have to look on the OUSA conferences to see and hear the hats being thrown into the air in delight, and all the whooping and hollering. So what has happened with M359?........I'm sure all will be revealed....

To infinity ... and beyond

[Silence]
To begin at the beginning:

Well, thats enough of Dylan Thomas for the moment. He resorted to alcohol when it got tough, but he produced some great poetry through it. But for an M359'er alcohol was the last thing on the mind. Cramming it full of every fact, every technique, every thing that I could so that I might stand a chance in the exam ... and now waiting. Waiting for the long nights and short days of December. And a result.

One thing is certain - there's no distinction this time! But will it be a 2 or a 3? Or will it be a fail? Almost impossible to fathom and I dare not think about it.

So now am in this gap, this place of limbo, between M359 and MT262. But the time is not being wasted. Instead, I am deep into restudying Java - not from the M254 books, but from other published work. Getting to grips again with Object Orientation and learning to 'do it properly'. What fun! So much better that those dark, sloe-black, slow black (note to self; stop this Dylan Thomas stuff) days and nights spent studying databases.

M359 - What I have learned

I was sitting down cogitating the other evening, and thinking about M359. The biggest thing that I think that I have learned during this course - is to make sure that I don't do any more courses on their first presentation. I have been amazed at the number of corrections that have had to be made to the course texts - and to the solutions to the exercises. It did not occur to me that a new course (or even a replacement course, such as M359) would have so many issues but, thinking about it now, I can see that it must be inevitable.

The OU seem to be over-hauling their Computing courses at the moment - several courses have completed their cycle and, for some of them, there is not yet a replacement. Clearly, it is a good thing that these courses are updated/replaced, but it does mean that there are several courses just about to have their first presentation - and I am going to avoid those like the plague - and that limits my choice. However, I think that I am sorted for the next 12 to 18 months...by which time I hope these courses will be on their second presentation!

M359 - TMA03 - Result

Well, I did moan back on Friday 13th July about how badly I thought I had done in TMA03 - I really felt quite hacked off about it. I am now making headway into TMA04 and ploughing, full-steam, through Block 4. But tonight, just for the hell of it, I thought I would check to see if my TMA had been marked. It has - and it was not quite as depressing as I thought it was going to be. I would have liked a higher mark...who wouldn't, but I'm happy that it was not the doom and gloom that I had convinced my self it would be.

Perhaps there is hope for me after all.

M359 - Oh no - its back to front!

I have just made a startling discovery....all through this course I have been mis-reading E-R Diagrams with regards to participation. I just don't believe it. Take a diagram that has two entities and lets call them Teacher and Student. Now, suppose there is a relationship between them such that a Teacher can teach many students and a Student can be taught by many teachers. Seams reasonable. Lets also assume that not all teachers are always teaching - sometimes that will take time out to research (I have a friend who is a Professor of Law. Sometimes he has PhD Students to supervise, othertimes he is researching and writing books and has no students). So there is a many-to-many relationship but the participation is different at each end - for Teacher it is optional but for Students it is mandatory (otherwise they are not students). So far, so good. The error that I have made to date is to think that the symbols for participation, which on this course is an open or closed circle, went at the end of the relationship that also give the degree of participation. What I have done in the past is to place the symbol at the end that also shows the degree of participation - but what I really should have been doing is placing it at the end adjacent to the entity type that it relates to. Thus, if the Teacher entity type has an optional participation, then the open circle goes at the Teacher end. It seems so &%**"~ obvious now that I find it hard to believe that I thought it was different from that.

(Yes, I know that Students sometimes take a gap-year, so in that period they don't have a teacher - but I guess that they are still students. But that doesn't alter the main point of me realisation!)

M359 - TMA03 Done - and so am I.

Well, it has been a long, long time. M359 has taken up more time that I thought it would - and TMA03 in particular has been a real pain. In the end I ran out of time to make a proper job of it, and have had to submit it in what I think is a less than satisfactory state.

The net result of all this is that I am really going to have to work at being motivated - and that is going to be a struggle. Oh, yippy.

On the positive side, there is only one more TMA to do and then the exam. And then I am going to take a break from my studies - I need time to recharge, and my family need time from me.

M359 - TMA02 Submitted

Well, thats it. TMA02 is submitted, all done and dusted. I had problems with parts of this TMA - Question seemed to be too easy (so now I'm worrying that I have mis-read, or misunderstood, what what really required). Question 2 was an interesting challenge - particularly all the constraints that we had to write - and this is the question on which I spent most of the time and effort. Question 3 was fairly straight-forward, and question 4 was just great fun (yup, really).

And so now the waiting begins. Main hope is that I do better than the rather poor 75% I received last time. Main worry is that I will do worse that the rather poor 75% I received last time!

M359 - Thats Another Fine Book I've Got Myself Into

I recently bought another book to help with the M359 studying. This one is by Thomas Connolly and Carolyn Begg and takes a similary approach to database theory and design that the M359 Course Team have taken. A few differences - including the way the doing their E-R Diagrams (they use standard UML - no problem). Its quite a hefty book running in, as it does, at 1300+ pages but I am finding a usful adjunct to the course materials. I'm still refering to Chris Date's 'Database in Depth' that I mentioned in a previous post (which also has the benefit of being quite easy to carry around - unlike Connolly and Beggs paving-slab of a book).

M359 - TMA01 Result

Well, a bit disappointed with my result for TMA01 - just 75% - which is the lowest TMA mark I have ever received. But no matter - onwards and upwards - the key thing is to learn from it.

But the mad thing is that I lost most of the marks for stupid, piddling, little mistakes - like forgetting to name a relationship, even though I had correctly worked it out. I'm not complaining - I know its important to get these thing right, but if I could kick myself up the backside, I would (no, don't try and picture that). I also missed one of the attributes of a compound primary key - why? haven't the foggiest. It was all down in black and white in front of me (even my scribbled notes show that I did the work correctly) but when it came to typing up the TMA I just missed it out. Foolish me. And, worse still, missing out that attribute had a knock on effect on the remainder of the answers.

Oh well, at least I have a target for the next one that I know is beatable!

M359 - TMA01

Well, thats it. TMA 01 is submitted, for better or worse. I try and not submit TMA's until almost the last minute just in case something occurs to me (along the lines of: "So thats what the question meant! I'll have to redo all that bit"). But I found that for the last week or so I have just been fiddling and tinkering with it but not really making it any better. So the time has come to put it to rest and see what comes.

Never quite sure with a new course just how the marking is going to go, so all I hope at present is that I haven't fluffed it and have taken the correct approach and level in answering the questions. What I would like is to achieve above the 85% line (and generally, in previous courses, I do). But ...

M359 - Self-Help Session

We had our first 'self-help' session at Saturday. These sessions are rather like the chat you might have over a canteen table at a bricks and mortar university. We get the chance to meet up, talk about what we find difficult on the course, encourage each other and generally help each other out. I find these really useful, especially when I feel that I am stuck. It always useful to get someone else's take on something - perhaps they have a different point of view, perhaps they interpretted something differently. It all helps to widen out the way we think about problems and how we tackle them.

The only problem with these sessions is that so few fellow students turn up. On Saturday there were just three of us. Don't get me wrong, we covered a great deal of ground and it was very useful - but I am sure that other students would benefit too, and the more voices that chime in, the more we all learn.

But it is odd. When I did M206 a couple of years ago we held regular self-help sessions and only three or four people ever turned up for those too. And here's the really odd thing - on previous courses, the people that needed the help and advice the most where the ones who didn't turn up. Explain that!

M359 - Conceptual Data Model - problems

Its been a frustrating week. In the course materials we are given a scenario for a University (well, what a surprise!) and a Conceptual Data Model that goes with it. The problem that I have had is that the Entity-Relationship Diagram shows an entity called Staff and another called Course (there are many other entities too). These two entities are linked by a one-to-many 'TelephoneTutoredBy' relationship with the 'one' being at the Course end and the 'many' at the Staff end. My reading of this is that each Course must have one, or more, staff members who do TelephoneTutoring for it. There is also a constraint that says that the staff member doing the telephone tutoring must also tutor at least one enrolment on that course. All pretty straight-forwards.

But the course text then went on to say that a staff member could ONLY telephone tutor on ONE course - and I couldn't see where this was stated in the Conceptual Data Model - there didn't appear to be any constraint anywhere saying that. I raised this as a question on FirstClass. Some responses said that the phrase "...staff member can only be a telephone tutor for a course if they are..." really meant "...a staff member can only tutor for ONE course if they are...". I don't buy the idea that 'a' really means 'one' - its ambiguous. If they had meant 'one' then they would have written 'one', surely. Another respondent suggested that it didn't matter and that I should just ignore the ambiguity (really!). After several days of pondering over this, there was a posting by the conference moderator who had written a guide to interpretting CDM's that went some way towards explaining the situation - but I still felt uneasy.

In the end I think the penny has finally dropped - the Entity-Relationship Diagram is only part of the model. Following the ERD is a list of 'Additional Constraints' that go on to clarify, or complement, the ERD. I think my problem was that I had glossed over the word 'Additional' and had interpretted it as being the textual representation of the diagram (ie; two facets of the same thing - they are not).

Having said that, I still don't see anywhere in the whole Conceptual Data Model where it says that staff can only TelephoneTutor on one course - but I am going to let it lie - the course text clearly make the assumption that it is.

Time to worry about the TMA!

M359 - Constraint Checking

Just had an interesting, but inconclusive, FirstClass conversation regarding turning off Constraint Checking while performing a bulk load of data into a database. My view was that we have constraint checking for a very good reason: ensuring that the database remains consistent - because as soon as the data is inconsistent it then become unreliable, and if its unreliable then people will not use or trust it. So its pretty important!.

So the idea of turning off constraint checking during a bulk load sounds almost like suicide to me. But, it was pointed out that during a bulk load you are probably populating one table at a time, and if the table that a constraint depends upon is currently empty then the import will fail. So you HAVE to turn off constraint checking. A side effect is that it speeds up the import - well, to me that would be a side effect, but it has been suggested elsewhere that it might be considered to be a primary motive (!?).

But what really bothers me here, and so far no one has been able to convince me otherwise, is that if the data you are importing comes from another source over which you have no control, how do you know that the data is already consistent? And if it isn't consistent, and you have constraint checking turned off, you now have an inconsistent database! That can't be right.

One of the contributers to the discussion said that when constraint checking is turn back on after the import, error messages will be issued for any constraint that fails. I guess this is some help.

I'm still not convinced - there must be more to this.

M359 - Books

I have been reading this book by Chris Date. I have often found that reading the course books supplied by the university is not enough - not that I think that the university books are bad, they're not - its just that sometimes I need to see things written differently before they sink into my dense numbskull of a brain that I have.

Anyway, I like this book. There's no doubting that Date knows his field. And he worked alongside Ted Codd. Its also clear from the outset that Date's view of SQL is, how shall we say, not very favourable. In fact, on Page 2, he states "SQL /= The Relational Model" and goes on to say that if your only knowledge of the Relational Model comes from your knowledge of SQL then you don't know the Relational Model!. He couldn't really be any ore clear than that.

I like his writing style. Quite short and succinct. A little bit of humour - but just enough - not like one computing book I started to read, where the author dribbled on advising his readers to go and get a coffee while they thought about some stunning statement he had just made. He lost me as a reader almost immediately! Strangely enough, I can't remember the name of the book, or the author - thats the kind of impact it made upon me. Anyway, I digress.

But its early days - I'm still only on chapter 1. But my gut feeling right now is that I will last out until the end of the book and that it will help me with this course.

M359 - Studying Technique

I prevaricated earlier about which note taking technique to use. On previous courses I have taken copious hand-written notes and found that I very rarely ever went back to them, although the process of note taking seemed to help some of the information sink in.

This time I have forsaken the pen and paper approach and have been making notes in Microsft Word. Trouble is, I have realised that I am making even more notes than ever. This is going to make life harder than it need be I fear - so I have to find a way around this. I have also started to create my own glossary of terms (since one is not supplied as part of the course). For this I am using a good and trusty text editor. I can then use the sort command in the editor so that my glossary stays in alphbetical order. And in case you are wondering which text editor can sort lines, the anser is 'Kedit'. Kedit is based upon, and very similar to, Xedit that is used on IBM VM/CMS systems. I started using Xedit back in 1983 (when, for me, it replaced 'Edgar' its fore-runner). Xedit has always been a favourite of mine - very flexible, a decent language for writing macros (that language being REXX). So the editor is fully extendible, provides all kinds of sorting, manipulation and so on.

M359 - Making a Start

At last I am under way with M359. One week in and I have just finished chapter two of the first course book - which means that I am a week ahead of schedule. But there is to be no let up - I know that if I let it slip then it won't take long for me to be behind schedule, and catching up is always hard to do.
So, we have covered the usual sort of stuff for the beginning of a course - what is data, what is information, what happened with data historically - Mesopotamian tablets, 15th Century Tally Sticks, 16th Century Parish Registers. How computerised databases came about, why was there a need, what types, how they have evolved.
Now we have getting down to the three-schema model, seperation of concerns, and all that stuff.
First TMA is also available and due to be started yesterday but covers subject matter that, officially, we don't cover on the course for another two weeks!

Keep it comming.

M359 - Some progress

Still worried. I have access to the M359 Course Website as of yesterday, and to the M359 First Class Conference as from this morning - but still no sign of any course materials. That's nine days now since they were dispatched. I wonder which company they use for their deliveries.

In the meantime, I am puzzled as to why there is only one conference for M359. With other OU courses that I have studied there have always been several conferences - a general social chit-chat conference, a general course conference, a tutor-group conference, and then a seperate conference for each TMA. I hope that these other conferences will start to appear soon - the OU must have know that M359 was starting in February!

M359 - Still nothing

Well, two days to go until the course officially starts and still no sign of any course materials, access to the course website, or to the Course Conference on First Class. So, being slightly worried about this I telephoned the OU Computing Help Desk and explained the situation. A few checks by the man on the phone and his response was 'oh yes, you do seem to have some services missing' (which is fine, but I had already guessed that bit!). He said he will forward the request on to the appropriate team at the OU so that they can give me access. The good (I hope) news is that their records show that the course materials where dispatched by land-snail on 24th January.

So.....I'll just keep waiting and hoping.

Also today, I had an letter from the course Tutor, Dorothy Carrier (or, Dot Carrier, as she prefers to be called), just welcoming us all to the course and giving us some of her background. A useful letter I thought. I have responded by email and relayed some of my background to her.

M359 - Study Techniques

For each of the courses that I have done so far, I have used slightly differeing techniques for studying - and I was reviewing some of these yesterday. One thing I noticed that was common to all the techniques is that I tend to write down far to many things. I was looking at my notes for M206 that I did a couple of years ago and see that I managed to fill two A4 hardbound books with everything you could think of (and more). But I am not sure that it helped - especially at revision time - too much to take in, drowning in data but lacking in concise and clear information. In fact, when I studied MU120 I definitely found it hard to use my notes.

So, what to do? Two choices I guess. I could really cut down on my note taking, or, I could produce some kind of index to all my notes.

I think I favour the former approach for two reasons - one is that it takes so long to make all these notes, and thats time that could be better spent doing practical work and, secondly, having spent so much time making notes, I'm not sure that I want to spend even more time creating indexes. Unless I can find some good note taking software that will doing my indexing for me.

Watch this space....