The space between _ and 1 was intentional (and actually
the source of a problem for one student). For an experienced J
person (like yourself) the intended meaning and way to express it
are obvious. But to a novice, and particularly one from the "pen
and paper" tradition, the significance of whitespace may not be the
first thing that draws their attention. It may not even draw their
attention at all.
This example is not a criticism of the language. (For me, the highly
systematic design of the language is one of its main attractions.)
Rather, it is a reflection on a source of difficulty students have with
learning the language, which I expect applies generally.
Steve
Björn Helgason wrote:
Possibly a typo
First is a space between the _ and 1
*: _1
_ 1
Second *: is square
*: _1
1
%: is square root
%: _1
0j1
2007/3/1, Steven Phillips <[EMAIL PROTECTED]>:
I am teaching J to non-native English speakers (Japanese university
students)
as part of an optional Technical English course for engineering
students.
The main objective of the course is to gain experience at listening
to and
presenting in English. The topic could be anything, but I use J
because it
allows you to do computations with little fuss and in
a radically different way than a procedural approach.
Response to the J part of the course has been mixed, keeping in mind the
wide range of abilities in both English and programming. On the positive
side,
students get an insight-like (aha!) feeling of discovery when they
can see
the meaning behind the symbols. However, getting to this point requires
breaking some long-held assumptions over what the symbols mean
(e.g., confusing the use of "-" versus "_"; or "_1" versus "_ 1"). It
may
seem obvious to an experienced J person and hence hardly worth more
than a passing remark, but these are the sorts of things that can really
block progress when attention is drawn to a more complex expression. For
example, students can get stuck on even the simplest expressions like
*: _ 1
_ 1
which looks like a bug - square of negative 1 is negative 1. In trying
to work out what went wrong, a student may tend to focus of the part
that is not immediately obvious (*:) and fail to question the more
basic assumption that _ 1 means negative one. Casual experimentation
can even reinforce the false assumption that space is not significant:
-1
_1
- 1
_1
_1
_1
_ 1
_ 1
Steve
----------------------------------------------------------
Steven Phillips, PhD
Cognitive and Behavioral Sciences Group,
Neuroscience Research Institute, AIST
1-1-1 Umezono, Tsukuba Central 2, Tsukuba, Ibaraki 305-8568 Japan
Tel: +81 29 861 5165 (PHS: 45165) Fax: +81 29 861 5857
WWW: <http://staff.aist.go.jp/steven.phillips>
----------------------------------------------------------
Steven H. Rogers wrote:
> I'm doing an informal survey on the use of Array Programming Languages
> for teaching. If you're using J in this manner I'd like to hear from
> you. What subject was/is taught, academic level, results, lessons
> learned, etc.
>
> Regards,
> Steve
>
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>
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