One consequence I've found of the research interest mechanic is that it makes it worthwhile to devote ultra-poor and even poor worlds to nothing but research. Use your whole empire one turn to jumpstart research on a project, and then let just slowly accumulate research from there with research coming from only your factory-less poor world.
If you used a poor world to build factories and ships and stuff, it would only be half as effective. If you use a factory-less poor world to build tripled research, it becomes 3/5ths as effective as a normal world with factories, which is better than half. (You multiply by three due to the research interest bonus, and divide by 5 due to the fact that with factories you would be producing 5 times as much production per population point). This assumes zero cleanup costs. If you are spending a lot of your factory output on cleanup, like you do at the beginning of the game, then a poor world becomes even more effective when devoted to research only.
If you want to talk about ultra-poor worlds...well, when building factories it is only 1/3rd as effective. When building tripled research without factories, it is once again 3/5ths as effective as a normal world with factories, which is faaaaar better than 1/3rd.
Plus, you get immediate payoff from the technology research (and often savings when building ships at all of your other planets), whereas factory construction takes time to pay off.
The moral of the story? Only when you have significant factory cost upgrades and cleanup upgrades does it become worth it to build factories at poor and ultra-poor worlds. Otherwise, you are better off making them your steady research centers, with a little help from other planets for the initial investments.
If you used a poor world to build factories and ships and stuff, it would only be half as effective. If you use a factory-less poor world to build tripled research, it becomes 3/5ths as effective as a normal world with factories, which is better than half. (You multiply by three due to the research interest bonus, and divide by 5 due to the fact that with factories you would be producing 5 times as much production per population point). This assumes zero cleanup costs. If you are spending a lot of your factory output on cleanup, like you do at the beginning of the game, then a poor world becomes even more effective when devoted to research only.
If you want to talk about ultra-poor worlds...well, when building factories it is only 1/3rd as effective. When building tripled research without factories, it is once again 3/5ths as effective as a normal world with factories, which is faaaaar better than 1/3rd.
Plus, you get immediate payoff from the technology research (and often savings when building ships at all of your other planets), whereas factory construction takes time to pay off.
The moral of the story? Only when you have significant factory cost upgrades and cleanup upgrades does it become worth it to build factories at poor and ultra-poor worlds. Otherwise, you are better off making them your steady research centers, with a little help from other planets for the initial investments.