Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cwjcc!gatech!udel!rochester!crowl
From: crowl@cs.rochester.edu (Lawrence Crowl)
Newsgroups: comp.lang.misc
Subject: Re: Coverage of multitasking
Message-ID: <1989Aug21.210122.4460@cs.rochester.edu>
Date: 21 Aug 89 21:01:22 GMT
References: <12126@orstcs.CS.ORST.EDU> <6291@hubcap.clemson.edu>
Reply-To: crowl@cs.rochester.edu.UUCP (Lawrence Crowl)
Organization: U of Rochester, CS Dept, Rochester, NY
Lines: 34

In article <6291@hubcap.clemson.edu>
billwolf%hazel.cs.clemson.edu@hubcap.clemson.edu writes:
>From article <12126@orstcs.CS.ORST.EDU>, by rudolf@neptune.uucp (Jim Rudolf):
>> The way people learn things best is to compare them to things they already
>> know or have experienced.  So in the case of teaching parallel algorithms,
>> I tend to believe that most people think sequentially, and have a difficult
>> time with parallel concepts.  
>
> Which they can compare to things they already know or have experienced;
> practically all social activity is an example of parallel computation.
> Corporations get the job done by hiring lots of little sequential processors
> and getting them to perform parallel computation.  On what basis do you
> believe that parallel concepts cannot be (as opposed to "haven't been in the
> past") explained in a natural manner?

The concept of parallel work is easy to explain.  The difficult part is
teaching people to manage parallel work correctly.  There are endless
management tools (PERT charts, etc) that aid managers in coordinating and
scheduling all the parallel activities of their employees.  If managing
parallelism were in any way natural, we would not need the managment tools
and would not need to pay managers so much.

While people often manage limited parallelism routinely (cooking two dishes at
once), they need considerable training and experience to manage more.  In
addition, most such tasks have a considerable amount of slop in them.  For
example, turning the heat down on the potatoes and up on the grean beans can
be done in any order.  Not as much slop exists in computation.

Also, note that almost all programming is done at the cognitive, or linguistic,
level of thought.  At this level, thinking is almost entirely sequential.
-- 
  Lawrence Crowl		716-275-9499	University of Rochester
		      crowl@cs.rochester.edu	Computer Science Department
...!{allegra,decvax,rutgers}!rochester!crowl	Rochester, New York,  14627