Altshuller took a large sample of patents from 14 different classes published in USSR and analysed the levels of their invention. Altshuller made 5 different levels of invention and classified those patents into those levels. The distribution pattern of the sample patents in five different levels of invention is as follows.

[The percentage of the inventions in different levels are based on the study made by Altshuller in 1982. The statistics may varry to some extent in different sample of patents.]

1. The standard solution: this is typically a quantitative change without new quality. Something like choosing between a few obvious alternatives. This is done by using the knowledge within one's profession. Roughly 32% patented solutions fall under this category.
Example: Additional function keys on a computer keyboard.

2. Change of a System: in this level of solution the object is changed qualitatively but not substantially. This uses knowledge of the industry. 45% of patents fall under this level of invention.
Example: A fire extinguisher attached to a welding device.

3. Solution Across Industries: In this level of solution, the object is radically changed. Not only the knowledge inside the industry, but knowledge outside the industry is also used to bring this level of solution. About 19% of the patented inventions fall under this category.
Example: Mouse as a pointing device in the computer.

4. Solutions Across Technology: A new object is created. The solution is created not only the knowledge in the industry but also the knowledge of Science and Technology. The solution is chosen out of tens of thousands of possible variants. Only 4% of the patented solutions fall under this category.
Example: Integrated circuits, Personal Computer etc.

5. Discovery: In this level, the solution is based on a scientific discovery. The solution is chosen from millions of possible variants. Only 1% or less of the solutions fall under this category.
Example: Radio, watch, bicycle, aeroplane, photograpy etc.

Level of invention	Improvement	Number of variants	Knowledge used	% of patents
1. The standard solution	trade-off, quantitative changes	a few	company knowledge	32 %
2. Change of a system	qualitative change	tens	industry knowledge	45 %
3. Solution across industries	radical or fundamental change	hundreds	knowledge across industries	19 %
4. Solution across sciences	new system created	thousands, tens of thousands	knowledge across technology	4 %
5 Discovery	breakthrough, new discovery	hundreds of thousands, millions	knowledge across science	0.3 %

Thus we find that most inventions are routine design solutions or improvements to existing systems. There are very few inventions (less than 1%), which are really scientific discoveries.

According to some TRIZ researchers, the recent patents are falling more in the lower levels of invention. If we take a sample of recent patents, "Solution across sciences" (4th level) and "Scientific Discoveries" (5th level) are found to be very neglegible in number.