which direction do you cut cardboard

[Cliff Stamp]

IF there is not stastical significance, proper sample sizes, proper bounding, etc, does that really diminish a reviews value in any way?

You can always be more informative. However it takes time and effort and it usually takes much more of each for ever gain you try to make so it quickly becomes impossible to go any further. It is pretty absurd to critize someone for not obtaining a particular standard of precision for work which is provided to you free of charge. The posts here are because people enjoy working with knives and want to share what they have learned. Appreciate it, culture it and encourage it.

How about a review that says" Got the knife, cuts great, about the same as a NIB Endura, and holds and edge about like a Victorinox paring knife, opens like a Buck 110." IS that review worthless because it is not "scientific"?

There is no actual requirement of precision in the defination of scientific. Some published work is really uncertain, meaning you only know the magnitude. Some of the work our lab group did had to do with quantifying an effect which was essentially a second order correction and all that could be obtained agreement wise between theory/experiment was basically the size (meaning no precision) but that still is enough to publish. You just hope that you can refine this later on. As long as you actually learned something then by defination it is scientific. Science is just about learning and doing something in a scientific manner just means it enables you to learn. Realize that there was science long before there were any physical instruments to measure anything.

There of course are grades. Anyone who does research is constantly refining their methods of both data collection and analysis and basically every paper tends to reflect this because if it didn't it would mean you didn't actually learn anything which is kind of sad unless you think you have obtained perfection which is pretty absurd. Plus even if you are completely up to date then there are always people refining algorithms and such. Pretty much for every little thing you do there are a dozen guys who have that as the primary focus of their work and you can always learn from them.

You will see this readily in reviews. Just look at comments some of the active members make about performance now as compared to even a few years back. As they get more experienced then it is reflected in their comments. The best way to encourage the type of work you want to see is also to lead by example and show the benefits.

I have seen Cliff complement subjective reviews and I don't think he said in this stream that he found no goodness in such.

I appreciate all information as long as it is honest and unbiased and I am not being decieved so as to sell me something. If someone wants to just talk about their impressions of a knife based on completely informal EDC carry that is great. If they carried more than one knife and will compare them then so much the better. If they want to be like Sodak and try multiple angles on multiple steels with the same cutting material then excellent.

Most people are open to actually offering more information if you use ask. I can't recall a lot of times when I asked for more details and they were refused. Most people are in fact very willing to share their opinions and experiences if you just give them respect. Of course if you come in like a nob and start attacking them because they don't do things the way you think they should be done then that isn't conductive to anything besides being a troll. Of course salemen won't be overly helpful with discriminating commentary but then again they are salesmen and you don't expect it anyway.


-Cliff

 

[knifetester]

It is pretty absurd to critize someone for not obtaining a particular standard of precision for work which is provided to you free of charge. The posts here are because people enjoy working with knives and want to share what they have learned. Appreciate it, culture it and encourage it.

Exactly.

The absurd personal attacks and pointless objections that go on here (at times) really has a chilling influence. I am sure there are lots of people out there that would love to post on subjects, but choose not to just to avoid the BS and hassle.

That is why a return to civility is what is largely needed, not just here, but at many on-line forums. WWJKMD?

 

[Dog of War]

IMO you don't have to cut much cardboard to figure out that it's a relative test medium rather than an absolute. A stark comparison is the thin, single ply cardboard used in 6 and 12 packs of beer and soft drinks, and the light corrugated cardboard in US postal service priority mail shipping boxes. The beverage boxes cut easily but obviously have so much grit and inclusions that sharpness deteriorates rapidly on any knife (in fact I've been testing them lately as a way of removing difficult, near microscopic wire edges and it seems to be working real well!) Priority mail boxes, however, are at the other extreme, you can cut for many feet with a good blade and barely detect any loss of sharpness after the initial drop-off of an edge optimized for push cutting.

This is why tests of edge retention cutting cardboard are most meaningful when blades are compared side-by-side on the same cardboard stock and then repeated enough times to have some degree of significance. This controls for variations from lot to lot, manufacturer to manufacturer. Take even one blade used in previous testing and you can gauge performance of additional blades with different cardboard stock. This isn't any different from cutting used carpet, which I didn't quite understand at first .... sure you're not controlling how much and what kind of grit got tracked and ground into it, but that gets factored out with repeated side-by-side testing on the same carpet.

 

[Cliff Stamp]

I am sure there are lots of people out there that would love to post on subjects, but choose not to just to avoid the BS and hassle.

Preventing such posts is the main purpose of a lot of the personal attacks, this is why the demands/commentary isn't consistent.

This is why tests of edge retention cutting cardboard are most meaningful when blades are compared side-by-side on the same cardboard stock and then repeated enough times to have some degree of significance.

Yeah, different stock would be a significant systematic deviation which could easily skew performance. You don't want to use one knife to carve pine and another seasoned oak. The critical thing is random sampling to insure there isn't a systematic deviation, this goes beyond materials.

If you do a lot of something you will get better at it. You have to consider this if you compare recent work to something you did a year ago. A blade could have superior performance even if the steel/geometry was actually no different. You need a common benchmark to again prevent a systematic deviation.

This isn't any different from cutting used carpet, which I didn't quite understand at first .... sure you're not controlling how much and what kind of grit got tracked and ground into it, but that gets factored out with repeated side-by-side testing on the same carpet.

Yes, again just use random sampling. Carpet composition is so random that you need median or similar statistics. Grate an edge along a big rock in the middle of a run and reduce the cutting ability to zero. This will severely skew the results of an average but the median isn't influenced at all by the size of the outliers which is why it is very good for data sets which have really high magnitude deviations. If anyone is unsure of how to handle these issues I'd be glad to write the necessary code to perform the computations.

-Cliff