From mboxrd@z Thu Jan 1 00:00:00 1970 From: Carsten Dominik Subject: Re: Estimate ranges in column view Date: Fri, 18 Jun 2010 09:04:10 +0200 Message-ID: <10E98231-262C-45D4-82A2-2B660068A55E@gmail.com> References: Mime-Version: 1.0 (Apple Message framework v936) Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Return-path: Received: from [140.186.70.92] (port=50734 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OPWLm-0004yI-8o for emacs-orgmode@gnu.org; Fri, 18 Jun 2010 03:50:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OPWLk-0001WO-F3 for emacs-orgmode@gnu.org; Fri, 18 Jun 2010 03:50:53 -0400 Received: from mail-ww0-f41.google.com ([74.125.82.41]:42204) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OPWLk-0001WF-Af for emacs-orgmode@gnu.org; Fri, 18 Jun 2010 03:50:52 -0400 Received: by wwb34 with SMTP id 34so650527wwb.0 for ; Fri, 18 Jun 2010 00:50:50 -0700 (PDT) In-Reply-To: List-Id: "General discussions about Org-mode." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org Errors-To: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org To: Mike Gauland Cc: emacs-orgmode@gnu.org Hi Mike, On Jun 17, 2010, at 10:06 PM, Mike Gauland wrote: > When planning my work, I estimate the effort required as a range, > rather than a > single value. That is, instead of estimating a certain task will > take 4 days, > I'll use a range of 3-5 days. If I'm a bit less confident I know how > long it > will take, I'll use a wider range (e.g., 2-6 days). > > When I first started doing this, I switched from using a single > 'Effort' column > in org mode, to two columns (Effort_Low and Effort_High), simply > summing each > column to get an estimate for a composite task. However, this > magnifies the > level of uncertainty in the estimate. The final 'Effort_Low' value > tells me what > to expect if everything goes optimally; 'Effort_High' provides the > extremely > pessimistic view. > > More realistic summaries come from considering the range of each > pair, using the > combined statistical variance in each (low, high) pair to determine > the variance > in the final value. This is the method used by LiquidPlanner, for > example. > > I've been mucking about with org-colview.el to automate this > calculation for me, > and am quite pleased with the results so far. I've approached this > by adding a > new summary type ("est") to org-columns-compile-map, and extending > org-columns-number-to-string and org-columns-string-to-number to > convert ranges > to and from strings. This lets me populate an 'Estimates' column > with values > such as "[2 4]", and specify a summary type "est" to have the > algorithm > described above used to produce the final estimates. > > I have two questions for the list: > > 1. Is this the right approach, or should I change the behaviour of > the > existing EFFORT property? Changing the existing EFFORT property would require more changes in other places for example in the agenda filter that filters by estimated effort, or maybe also in code that helps to set/change the effort property. So to make this fully work with the existing EFFORT property would probably require a lot more work. > 2. Is this something others would find useful? I like the idea of variance calculation for this purpose. So I would be inclined to take a patch that will introduce this new summary operator. Depending on how much code this is, you'd also have to sign the papers with the FSF (unless you have done so for Emacs already). To complete the patch, you could make things easy for my be providing a change to the manual, and by also doing the corresponding changes in org-colview-xemacs.el. But neither of these two would be required for acceptance. Cheers - Carsten