[R] Point and click

[Cliff Lunneborg]

The following query raises the question: What is it that students learn
from point and click dialogs?"

Date: Fri, 03 Oct 2003 16:57:42 -0400
From:
To: s-news at lists.biostat.wustl.edu
Subject: Splus question
Message-ID: <BAY9-F52Q7OoK42LpqI000238f3 at hotmail.com>

I don't know if this is the right list to post this question. If not,
please let me know where I should post this. I have a dataframe with 3
variables: ID, Y, Group Group is either 1, 2, 3. I am trying to run a
t-test to compare the three groups on outcome Y. I know how to do this
using the point and click dialogs. But can't get it to work on the
command line. When I type: t.test(y, group)  it just compares y and
group
as though they represent the two samples. I tried doing something with
tapply(y, group) but don't know how that works. If someone knows, please
email me. Thanks.

**********************************************************
Cliff Lunneborg, Professor Emeritus, Statistics &
Psychology, University of Washington, Seattle
cliff at ms.washington.edu