Here are my 9 proposed top-level topic categories-
  1. Water
  2. Food
  3. Public health
  4. Culture and community
  5. Communication and information technology (maybe just "Information technology" or "Communication and information")
  6. Energy (notice not Power and Energy as energy implies both)
  7. Land, materials and construction
  8. Transportation (most debatable, could fit some under energy, some under culture and then just have a Transportation portal)
  9. Metaconcepts (these will mostly be concepts that are implicitly incorporated in many different pages. They will be mostly definitions, that are linked to inline from the text of other pages)
These 9 top-level categories are based on 8 basic human needs-
  1. Water
  2. Food
  3. Health
  4. Community
  5. Knowledge
  6. Energy
  7. Shelter
  8. Transportation (arguable)

An example category tree based on these 9 top-evel categories follows.

Please note that many subcategories will be in multiple higher categories.

Water[edit source]

Water conservation[edit source]

Rural water supply in _______[edit source]

Greywater[edit source]

Garden box[edit source]

Planter box[edit source]

Rainwater harvesting[edit source]

Rooftop rainwater catchment[edit source]

Stormwater catchment[edit source]

Swales[edit source]

Pumping[edit source]

Hydraulic ram pumps[edit source]

Solar pumps[edit source]

Rope pumps[edit source]

Hand pumps[edit source]

Water quality[edit source]

Water storage[edit source]

Wells[edit source]

Cysterns[edit source]

Storage tanks[edit source]

Ferrocement tanks[edit source]

Plastic tanks[edit source]

Wood tanks[edit source]

Wastewater treatment[edit source]

Primary wastewater treatment[edit source]

Secondary wastewater treatment[edit source]

Tertiary wastewater treatment[edit source]

Physical wastewater treatment[edit source]

Chemical wastewater treatment[edit source]

Bilogical wastewater treatment[edit source]

Constructed lagoons[edit source]

Community scale wastewater treatment[edit source]

Water sanitation[edit source]

Filtration[edit source]

Slow sand filtration[edit source]

Distillation[edit source]

Desalination[edit source]

Solar desalination[edit source]

Water transportation[edit source]

Water jugs[edit source]

Food[edit source]

100 mile diet[edit source]

Companion planting[edit source]

Food preperation[edit source]

Macrobiotics[edit source]

Raw[edit source]

Vegetarianism[edit source]

Omnivorism[edit source]

Food preserving[edit source]

Canning[edit source]

Dehydrating[edit source]

Storing[edit source]

Seed saving[edit source]

Organic gardening[edit source]

Double digging[edit source]

Composting[edit source]

Vermiculture[edit source]

Pit compost[edit source]

Spinning barrel compost[edit source]

Agriculture[edit source]

Crop rotation[edit source]

Crop drying[edit source]

Crop storage[edit source]

Growing _______ in a ______ climate[edit source]

Fertilization[edit source]

Pest management[edit source]

Aquaculture[edit source]

Agroforestry[edit source]

Biointensive gardening[edit source]

Greenhouse[edit source]

Pit greenhouse[edit source]

Lean to greenhouse[edit source]

Attached greenhouse[edit source]

Freestanding greenhouse[edit source]

Hoophouse[edit source]

Animal husbandry[edit source]

Chicken tractor[edit source]

Animal health[edit source]

Beekeeping[edit source]

Public health[edit source]

Pest control[edit source]

Health care in _____[edit source]

ORT[edit source]

Cysts[edit source]

Prevention and treatment of _____[edit source]

Bacterias[edit source]

Prevention and treatment of _____[edit source]

Viruses[edit source]

Prevention and treatment of _____[edit source]

HIV[edit source]

Sanitation[edit source]

Hand washing[edit source]

Pit latrine[edit source]

Improved pit latrine[edit source]

Humanure[edit source]

Bucket composting toilet[edit source]

Double vaulted composting toilets[edit source]

(Many topics from water sanitation)[edit source]

Septic tanks[edit source]

Disabilities[edit source]

Human dignity in public health[edit source]

Refrigeration[edit source]

Vaccine refrigeration[edit source]

Food refrigeration[edit source]

Health paradigms[edit source]

Homeopathy[edit source]

Aleopathy[edit source]

Herbalism[edit source]

Culture and community[edit source]

Active citenzry[edit source]

Collaborative meeting tools[edit source]

Effective lobbying[edit source]

Environmental justice[edit source]

Multiculturalism[edit source]

Builiding partnerships[edit source]

Cities[edit source]

Community organizing[edit source]

Cooperatives[edit source]

Intentional communities[edit source]

Communes[edit source]

Ecovillages[edit source]

Social artistry[edit source]

Male contraception[edit source]

Banking[edit source]

Microfinance[edit source]

Triple bottom line[edit source]

Sustainable accounting[edit source]

Accounting practices[edit source]

Decision making techniques[edit source]

Pugh diagrams[edit source]

Delphi method[edit source]

Decision making structures[edit source]

Hand clasp[edit source]

Democratic[edit source]

Consensus[edit source]

Minority rule[edit source]

Majority rule[edit source]

Unanimity[edit source]

Communication and information technology[edit source]

Internet[edit source]

Open source[edit source]

GIS[edit source]

Repeaters[edit source]

Short wave radio[edit source]

Wikis[edit source]

Education[edit source]

Service Learning[edit source]

Teacher training[edit source]

Curricullum development[edit source]

Teaching materials[edit source]

Computer based education[edit source]

Education paradigms[edit source]

Piaget[edit source]

Montessori[edit source]

International programs[edit source]

Intereducation[edit source]

Energy[edit source]

Electrical energy[edit source]

Batteries[edit source]

Hydrogen fuel cells[edit source]

Microcapicitors[edit source]

Grid intertie[edit source]

Photovoltaic power[edit source]

Solar pumping[edit source]

Solar vaccine refrigeration[edit source]

Microhydro power[edit source]

Wind power[edit source]

Wave power[edit source]

Pedal power[edit source]

Heat[edit source]

Cookstoves[edit source]

Refrigeration[edit source]

Thermodynamics[edit source]

Solar thermal hotwater[edit source]

Hydronic radiant floor heating[edit source]

Insulation[edit source]

Stawbale insulation[edit source]

Fiber board insulation[edit source]

Fiberglass insulation[edit source]

Thermal mass[edit source]

Passive solar design[edit source]

Fuel[edit source]

Biogas[edit source]

Ethanol[edit source]

Biodiesel[edit source]

Materials and construction[edit source]

Natural capital[edit source]

4Rs[edit source]

Supplies[edit source]

Alternative materials[edit source]

Lechugilla[edit source]

Hemp[edit source]

Bioplastic[edit source]

Smartwood[edit source]

Material science[edit source]

Solid statics[edit source]

Solid dynamics[edit source]

Fluid dynamics[edit source]

Bioremediation[edit source]

Surveying[edit source]

Compost[edit source]

Alternative building[edit source]

Bamboo[edit source]

Papercrete[edit source]

Cordwood[edit source]

Earthship[edit source]

Tires[edit source]

Strawbale[edit source]

Ferrocement[edit source]

Living roof[edit source]

Earthen construction[edit source]

Adobe[edit source]

Cobb[edit source]

Bajareche[edit source]

Earth bags[edit source]

Earthen oven[edit source]

Earthen plaster[edit source]

Rammed earth[edit source]

Wattle and daub[edit source]

Stone and brick[edit source]

Transportation[edit source]

Greenbelts[edit source]

Busses[edit source]

Trains[edit source]

Light rail[edit source]

Bicycles[edit source]

Recumbent[edit source]

Rickshaw[edit source]

Bicycle parking[edit source]

Electric bicycles[edit source]

Critical mass bike rides[edit source]

Fuel[edit source]

Multiple occupancy vehicles[edit source]

Single occupancy vehicles[edit source]

Rideshare[edit source]

Metaconcepts[edit source]

Poverty Reduction[edit source]

International development[edit source]

Appropriate technology[edit source]

Sustainable development[edit source]

Permaculture[edit source]

Biomimicry[edit source]

Natural capital[edit source]

Triple bottom line[edit source]

Comments[edit source]

Place comments here.

Curt's first comments[edit source]

Looks good. I see this mostly as a major tuning of categories, but not something strikingly different (except that perhaps placing the top 9 categories under fundamental might be called "striking"). Here are some random questions:

I am happy with whereever you would like to place those 9 top-level topic categories. --Lonny
  • Sort of a general question about singular/plural. I see a lot of plurals, but Earthen oven is singular. Perhaps "earthen oven" is a concept, and not just an object, and that could explain the singular. (This question is really with respect to category naming policy of course, and not category structure.)
Earthen ovens (plural) is great and we should change it. But as far as a plural/singular policy: I added some more comments at Appropedia talk:Policy discussion#singularizing categories. --Lonny
  • It's still okay for some subcategories to appear in multiple higher categories, right? Fuel, for example, seems to belong in Transportation as well as in Energy, especially if a fuel serves dual (or more) purposes.
Absolutely. Fuel is in both of those categories. (I did not place the subordinate subcategories of Fuel on the second instance in the outline above only to save redundancy, clearly Fuel has the same subcategories beneath it in both instances.)
  • Since the table representation or presentation seemed well received, presumably this could also be placed in a table format. Would that belong in the Fundamental category page?
Table format would be great, I love it. I acquiesce to wherever you feel it should be placed. My only need is that it is linked directly from the Navbar. I think Category:Topics, where it currently lives, is the best place for it. --Lonny

Gotta run. I'm sure to think up some more questions, but there's nothing really surprising about this to me. --CurtB 07:46, 19 December 2006 (PST)

Excellent. BTW I am very excited to also have a expanding subcategory structure, similar to that at Wikipedia, e.g. Category:Physical_scienceswikipedia--Lonny 10:06, 19 December 2006 (PST)

Curt's second comments[edit source]

  • There is a threshold where category name length becomes painful to me. Consequently, I prefer "Information Technology" as the category name over the longer option.
  • I don't readily see the "land" connection...perhaps it's about "land use"? I can see Land as part of farming and agriculture..., but that would be under "Food". Where I'm going is that "Land, ... construction" is pushing my comfort zone on category name length, and I'm looking for a way to shorten the name, and "Land" doesn't fit naturally for me. Is "Land" a prominent enough category to participate in the name? I guess this is similar to me to the "refrigeration" topic. A useful category, but not really top level. (Having said all that, Lonny is going to give 12 examples of the importance of Land, and that's fine, I'll learn :-))
  • I agree that we should make efforts to keep category names succinct (if a name can be "succinct"... okay how about "short").
  • I think Aaron likes "Communication and Information" better, but I am okay with either, or even just "Information".
  • Although I am tempted by the challenge (12 examples of the importance of Land in under 1 minute)... I think I will concede to "Materials and construction". Please note that I have changed it above. --Lonny 15:05, 20 December 2006 (PST)

More comments from CurtB[edit source]

(warning, this is a "thinking out loud, stream of consciousness" comment)

This is a "metatopic structure" page, but while we're talking about topics, I want to open the discussion of hierarchy / topic depth. Basically, do we want a tree-like structure with 17 levels, with 6 items per level? Or do we want a tree-like structure with 6 levels and 17 items per level? (I realize that the math doesn't completely work. If the structure is a pure tree, then the capacity of a tree is (NitemsXlevels). That is, it's an exponential relationship, not multiplicative, and therefore not symmetrical in terms of ordering. That is, X^Y != Y^X (in C-speak).)

But my point is, assuming that we will have, say, 15,000 articles (my swag for a moderately mature article count) we are faced with the choice of many (many many) levels with a few articles or subcategories per level, OR, not so many levels with a lot more articles or subcategories per level. And we assume, of course, that one of the (or the only?) main purposes of topic categorization is navigation. (Even then, we must consider the "use cases": User starts from the root of the tree; User starts from article, clicks upward to topic category, then follows category structure..., is there another use case?)

Of course we (yep, I) must recognize that not every layer will be sweetly balanced, but let's see if we can target a range. (This, actually, is the critical,driving question. The structure will/shall/should be driven by the number of subcategories/articles at a given level.)

Cutting to the chase, I would really be bothered if the root-to-leaf path required more than 5 or maybe 6 clicks. I am not uncomfortable with 10 or 20 subcategories per level. If we choose that, and if the "average" span of a level is 7 (because we decide to split when we get to 14), then the capacity of a 5-click tree with 7 items per level is: 16,807. The math whizzes in the class will recognize what the capacity is if we "average" 10 per level.

What prompted this diatribe is that I am interested in porting the "Solar distillation" Tech Brief from Practical Action. I couldn't recall if maybe I had already ported this Tech Brief, so I searched and found the category "solar distillation". My gut reaction is that the category is too narrow. How many articles are expected under "solar distillation"? Hmmm...

Okay, after wandering around in the desert for 6 paragraphs, I think there is another factor. Perhaps there are only 3 articles related to solar distillation. Given the combo-linkage with water and solar, this is tricky. It's easy to categorize the articles under "distillation" on the water side. But where do they get categorized on the solar side? I guess we could put them under "solar hot water" since basically we are heating the water in order to distill it... But I need to be intellectually honest and say that such an approach "might" work here but doesn't handle the broader case....

Okay, so what I've realized is the need for some kind of topic categorization policy that includes the depth (from "root" to "leaf") and breadth (articles and/or subcategories per level) of the topic tree. I sahll go forth and work on a policy. (There is a larger "policy" discussion...basically, we need policies that are semi-established and not just on talk pages. I'll sign up to attempt that as well...someday after my first swing at non-profit incorporation.)

Lonny, this brings up a nagging question for me. How do people find our articles? Internet search? Topic tree? Link from other article? With subsequent questions: if no one uses our topic tree, does that mean we need to fix it? Or do we change our approach?

Warning: I promise to cogitate on this for a while, then come back and subject everyone to some more thoughts.

Signing off from the Big Island of Hawai'i, this is Approholic, --CurtB 18:33, 28 December 2006 (PST) (In my own self defense, my dream holiday would include many hours per day of Appropedia... What can I say? It's the pay, the benefits, the work environment, the team.)

Response[edit source]

Hi Curt,

(warning, this is a response to a "thinking out loud, stream of consciousness" comment)

Our category tree is not really a tree.
We are not building a strict taxonomy. For example, our categorization is not one-to-one (isomorphic), a subcategory can show up under more than one category.
Our not-really-a-category-tree will change weightings.
We cannot predict how many pages will be categorized under a category. For instance, Category:Solar_distillation could easily contain many organizations, projects and environment-based how tos.
Our not-really-a-category-tree will grow and change shape. New subcategories will continue to emerge from users. Over time new subcategories will develop and old subcategories may become obsolete.
Our not-really-a-category-tree is not really all that useful.
Most users will find our content from a link or an external search engine. Some users will find our content from the internal search engine or by browsing up the category structure. A few users will find our content by navigating down the category structure.

I think that more than building a perfect tree, we are seeding a folksonomy and building a categorization that we find useful. We should pick subcategories based on their existence in the world, and on their existence in Appropedia content. Instead of focusing on the not-really-a-tree, let's focus on the content. If you are looking to develop a policy, let us work more in the direction of user and content directed subcategories... something like: If a category has ____ number of pages related to the same topic, consider creating a subcategory for them and retagging the pages with the new subcategory.

Some additional reading:

What do you think? --Lonny 22:42, 28 December 2006 (PST)

Response to response[edit source]

(not sure about your formatting above...I removed line breaks from the external links, but not from the other lines)

I wasn't clear in my ramblings, but in the end I had decided that "Solar distillation" was an acceptable category. At the same time, your comments have definitely shifted my perspective on topic categorization. I must say that I'm not all that jazzed by the tagging stuff at, say,, but still recognize the value. It's one of those "not perfect, but better than all the alternatives".

My sense of the "strict tree structure" came from the early Topic page, where, under Water, the "Solar distillation" item said "see Solar". My bias was away from that strict tree structure, but a "tree-like" structure. Now I see that you're even less tree-like, and suddenly the larger Topic label makes more sense to me, and the metatopics as well. We may well have 500 topic categories. You can find them all under "Topic", or you can look in the subtopic categories (also fundamental categories) of water, energy, etc, etc and sift through a large number of "leaf" categories. Or something. Seems like max 2 or 3 layers of categorization with 50 subcategories per metacategory, then how ever many articles per subcategory. I think this math works. Another example of this is the way that Practical Action sorts their Technical Briefs. They don't have that many, so they all fit on a page. But they have about 7 larger buckets, and some articles fall into more than one bucket.

This will take me a bit to re-assess. My first sense is that I'll spend a lot less energy on topic category structure, since it seems to be relatively less important than I thought. At some point there is benefit (to contributors) in articulating our topic categorization policy, and so I'll approach it from that stand point.

If my newly developing understanding is near the mark, then navigation using topic categories is still valid, but it's accomplished more by performing a search for, say, solar distillation, then finding both a list of articles, plus a category. Choose the category or an article. From an article, you can click "upwards" to the category and find related articles. This is as opposed to walking the topic category pseudo-tree from the top.

--CurtB 09:20, 29 December 2006 (PST)

(thanks for pointing out those wierd linebreaks)
Your understanding seems close to the mark.
A couple of small tweaks -
Categorization may go deeper than 3 layers in some cases.
Search will bring you to the page you describe, but Go should bring you straight to the category page. I.e. all topic category pages should have a same-name page in the main namespace, which directs to the Category, e.g. Greywater goes to Category:Greywater, try Greywater Search vs Greywater Go.
Thank you for your continued efforts on refining both your understanding and the structure of our topic categories. --Lonny 02:13, 3 January 2007 (PST)

Sample table of category structure[edit source]

Here is a table that talks about category framework a bit more, based on extensive exchanges Lonny and I have had via email. Since this is a structure comment, I'm not sweating the plural/singular decisions here.

cells below contain category pages cells below (under the headings) contain article pages
Cat:Topic(s)are below /// Areas are to the right Cat:Projects Cat:How tos Cat:Principles (?) Cat:Organizations
Cat:Water Cat:Rainwater
Cat:Swales Portland example (empty) Beyond dams article Bob's swales
Ersson project Catchment how-to Beyond dams article Rain Harvest Association
Cat: Greywater Cat:Garden box (empty) Grey box how-to (empty)

In the table above, I propose the "Principles" area name for articles that are not quite Projects or How-tos. "Basics" seems too constraining, "Musings" seems too glib or lightweight for me. The need for this area category is not entirely clear yet, but if someone wants to see the list of such articles, it would be good to look here. We have several examples of such articles, like many from "Beyond Dams", as well as the "Power and energy basics" article. --CurtB 11:04, 20 December 2006 (PST) (sig line added by Lonny to break up conversation)

Power and energy basics seems more like it could be in a new area, such as Category:Lecture notes, could be Lonny's power and energy basics or Engr305 power and energy basics.
I based "Musings" on the following definition "to comment thoughtfully or ruminate upon."[1], and the incredible and very carefully worded Tech Musings of Don Lancaster (did I mention incredible). The "s" is used to signify the usage (and definitin) as a noun. But I hear what you are saying. I think that we should continue looking for the right name(s) for the area(s). Let's move this conversation to Category_talk:Topic/Draft_of_areas. --Lonny 15:05, 20 December 2006 (PST)

Content in Category pages[edit source]

How much content information belongs within Category pages themselves? Some are nearly empty, some have a lot of content. One view on the "principles" notion is that all that content could be placed in a category page. (Then the natural next question is, what about the principles of some subject that is too narrow to be a category?) My bias (just from my gut, without clear reasoning) is that Category pages should not have substantial content, except navigational content (like the table on the Topic page). What do others feel about this?

What are the benefits of placing the Topic category pages in Category:Topic? In part, if there are benefits, do we want to have a Category:Area that includes the area category pages? (The answer could easily be "no", since the Topic category pages are subject to much more growth than the Area category pages.)

What are the benefits to categorization generally? Are there more than those listed below?

  1. Navigation
    • especially for the topic categories
  2. Context
    • this benefit seems doubtful for me since category is very low profile, unless it is done through maintenance
  3. Maintenance
    • admins can sort thru groups of articles
  4. Intersections of categories (in future) seems like a very cool thing!

Enough for now... --CurtB 11:04, 20 December 2006 (PST)

Request for Commerce/Business/Trade and Manufacturing categories[edit source]

Hi Lonny! Happy New Year. You "threatened" to spend some more energy on the topic structure (and maybe even area structure) soon. (If you're essentially, done, that's fine, I'll start moving forward with what you've laid out above.) If you're going to make another pass, I want to request the insertion/addition of a commerce or business or trade subcategory, presumably within the community area. (May impact Banking? Is banking a valid term in Muslim communities? Lending?) Similarly, Manufacturing may go under Commerce. Commerce or trade seems more neutral than business, so could include cooperatives, I guess? (I bring this up since there are several apparently valid and useful Tech Briefs at Practical Action that deal with Manufacturing...). --CurtB 16:15, 2 January 2007 (PST)

Not-so-dramatic Major Categorization Suggestion[edit source]

Our current categorization scheme starts at "Fundamental", and then higher categories under there, of course. But not very many of the categories seem attractive from a navigation perspective, IMHO. What I would like is for the Fundamental category to be a highly usable for navigation purposes, and then have everything else tucked in a branch labeled (not really) "Uninteresting categories".

The categories that I think are most interesting for navigation are metatopics. Area categories are less interesting to me, but are at least moderately interesting. So my proposal is that Fundamental have only navigationally interesting categories, plus 1 catch-all for all other categories. Actually, I think this has been an implicit goal for others as well, and perhaps I'm just articulating something that's "out there."

As mentioned, interesting categories are, for me, the 9 metatopics, the 6 (or whatever) areas, plus one other high level category that holds everything else. Maybe that's "Appropedia management" or something. Alternatively, (and I'm just as happy with this option) would be 9 metatopic categories, one Area category (with all the areas underneath it), and one Management (or whatever) category for everything else.

I'll invest a bit more energy on this, but I wanted to get off my duff and at least articulate this much. --CurtB 09:58, 9 January 2007 (PST)

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