Tuesday, June 1, 2010

APPENDIX: Methods and tips for research, and for reporting and presenting results

Part of the reason for the complexity of Origins Science studies lies in how it sits at the intersection of several distinct disciplines: science, forensics, historiography, education, philosophy, theology, and maybe more. That means that if one carries out a research or field investigation project, particular attention needs to be paid to methodology and related grounding/ warranting of knowledge [[epistemology] issues. 

So, let us give a "rough working definition" of science as it should be (recognising that we will often fall short):
science, at its best, is the unfettered — but ethically and intellectually responsible — progressive, observational evidence-led pursuit of the truth about our world (i.e. an accurate and reliable description and explanation of it), based on:
a: collecting, recording, indexing, collating and reporting accurate, reliable (and where feasible, repeatable) empirical -- real-world, on the ground -- observations and measurements,

b: inference to best current -- thus, always provisional -- abductive explanation of the observed facts,

c: thus producing hypotheses, laws, theories and models, using  logical-mathematical analysis, intuition and creative, rational imagination [[including Einstein's favourite gedankenexperiment, i.e thought experiments],

d: continual empirical testing through further experiments, observations and measurement; and,

e: uncensored but mutually respectful discussion on the merits of fact, alternative assumptions and logic among the informed. (And, especially in wide-ranging areas that cut across traditional dividing lines between fields of study, or on controversial subjects, "the informed" is not to be confused with the eminent members of the guild of scholars and their publicists or popularisers who dominate a particular field at any given time.)
 As a result, science enables us to ever more effectively (albeit provisionally) describe, explain, understand, predict and influence or control objects, phenomena and processes in our world. 
In addition, origins questions are freighted with major consequences for our worldviews, and are focused on matters that are inherently beyond our direct observation. 

So, since we simply were not here to see the deep past ofr origins, we are compelled to reconstruct it on more or less plausible models driven by inference to best explanation. This means that in origins investigations, our results and findings are inevitably even more provisional than are those of operational science, where we can directly cross check models against observation. That further means that origins science findings are inherently more prone to controversy and debate than more conventional theories in science.

Consequently, IOSE course research projects have to be based on interdisciplinary approaches, and we need to develop skills for carrying out such research that cuts across traditional boundaries between fields, and for giving fair and balanced, but effective reports and presentations of what we have found out. 

But, then, that also means that origins science studies is a particularly good context for equipping us with the skills of thinking for ourselves, and for developing and presenting results and proposals for acting on the basis of such thinking for ourselves.

And so, we see the importance of this appendix.

A] Understanding scientific research:

One of the pivotal breakthroughs in science is Newton's theory of universal gravitation.

As is common in science, there is a bit of a suspect story that nevertheless captures the essence of the discovery. For, there we have young Isaac Newton, back home from Cambridge university on his family farm – taking refuge from the Black Death plague then racing across Britain's towns in 1666 – and sitting under an apple tree.

Plonk, an apple falls


(Some versions have it hitting him on the head. [[Newton, “often told the story that he was inspired to formulate his theory of gravitation by watching the fall of an apple from a tree.[[92]” At least, according to Wikipedia's article on Newton, and tracing though its reference no. 92, to Michael White's Isaac Newton: The Last Sorcerer. (Fourth Estate Limited, 1997), p. 86, [[This of course shows one way to legitimately use the often deprecated Wikipedia, to trace to more “respectable” sources for otherwise hard to find information.] )

He then notices the pale crescent of the New Moon in the sky, and a eureka moment happens: he “sees” that the same force that made the apple fall holds the moon in orbit around the earth.

That is, he has just inferred a key scientific explanation: a massive body like the earth warps space around it, creating a gravitational force field, i.e. a gravitational potential energy well; as we more usually term it. It would be “natural” to view such a field as spreading out evenly in all directions. That means we can see it as effectively flowing out from a point at the centre of the earth, so we can then see that as it spreads out through the spherical surfaces of surface area A(r) = 4 * π*r^2 we can imagine at increasing distances, r, from that centre, it will gradually become weaker:

Fig A1.1: Newton's eureka moment (Adapted: Friedman, SJS APC Physics.)

Immediately, we deduce that the intensity of the gravitational force will fall off inversely as 1/r^2, i.e. an inverse square law. That is, at double the distance, the rate of free fall will be one fourth. (And as well, we infer that the force field is on a per unit mass basis. That is, as Galileo's suggested leaning tower of Pisa experiment would have approximately shown, more and less heavy objects tend to fall at the same rate. [[NB: Air resistance effects would have made the heavier cannon-ball hit the ground just before the lighter musket ball.])

Now, from Eratosthenes' calculation c. 240 BC onward, reasonable estimates for the radius of the earth had been known. For, he was a founder of scientific geography [[his term, it seems], drawing a new “known world” map based on the line of latitude from Gibraltar to the Himalayas. Using the concept of longitude, he noted that at summer solstice, when the sun at noon was reflected from the water in a deep well at Syene [[now: Aswan], in Alexandria, “5,000 stades” roughly to the north, the shadow of an upright object is at an angle of about 7 ¼ degrees; meaning “5,000 stades” was ~ 1/50 the earth's circumference. So, he got an estimate of this within 10 - 20% of the correct value, i.e. just short of 25,000 miles or just over 40,000 km. And ever since, refinements have been made. [[Cf. Colin Ronan, The Cambridge History of the World's Science (CUP, 1983), pp. 117 ff. (1 stadion ~ 500 “modern” ft.)]

Similarly, it is possible to estimate the distance of the moon from the earth. For example, since there are known features on the Moon, an observer in London and one in Paris or Rome, etc. could arrange to look at the same feature at the same time, then use the known distance between cities and the measured angles to the feature on the Moon, to work out the triangle. (Cf. an exercise here.)

But in fact, when the Greeks from the “school” of astronomy in Alexandria used the above “known” size of the earth to deduce the distance to the moon, they didn't have fine enough instruments to do such a direct measurement. Instead, they used a bit of geometry and the observations that from earth the moon is the same angular size as the sun; while the diameter of the shadow of the earth on the moon in a lunar eclipse is about 2.5 times the moon's diameter, and they already knew that the cone of shadow is ~ 108 earth diameters long. (This last can in principle be seen by observing the taper of the shadow of a coin of known diameter that just blocks out the sun, making a small scale similar triangle. But, it is dangerous to look directly at the sun [[that's what probably helped to make Galileo blind for the last decade or so of his life . . . ], so instead of doing it the way the Greeks probably did [[moving a wood prism along a calibrated beam lined up with the sun, to just block the sun], one can substitute the full moon for the sun.)

Dr Fowler of UVa (as just linked) will not mind our borrowing his handy sketch, under fair use:

Fig. A1.2: Working out the distance to the moon. (Source: Michael Fowler, UVa Physics Department)

By similar triangles ABC, AEF and CDE, the already worked out result that BC = 8,000 mi, and with the known ratio EF = 2.5 * DE, the moon can be shown to be about 240,000 miles from the earth's centre. 

Extending this, Aristarchos [[~ 310 – 230 BC] used the fact that when the moon is exactly half-illuminated, it is at right angles to the sun, and so by observing the angle between the two in the sky, he estimated the relative distances and sizes. However, his measured angle was about 20 times too big: 3 degrees, so he thought the sun was ~ 20 times the moon's distance and diameter (instead of ~ 400), but that meant it was much bigger than the moon or the earth, and he proposed a heliocentric theory of the solar system. However, such a view did not fit well with the philosophy and the “common sense” of the time, which both seemed to supported the idea that the rest of the universe moved around the earth. (A systematic, biasing error in his method – in addition to the usual random errors that cause scatter with multiple observations -- is that depending on where an object is in the sky, its real direction is distorted by refraction at different angles through the atmosphere. Astronomers now routinely adjust for this.)

Newton knew the results of such work, and so he could work out the force and acceleration on the apple and the force on the moon that pulls it inward into a nearly circular orbit. His rough calculation “answered pretty nearly.” [[It was about 10% out from what one would expect on the theory.]

Along the way, he had also drawn together his famous three laws of motion (in one form or another these laws were known, but not pulled together in a fully useful unified pattern). He also needed to further develop the calculus to work out how the force of gravity of a large ball like the earth could be more or less treated mathematically as though it were flowing out from a point at its centre.

Newton's law of gravitation was very successful, and is in fact still used to calculate the mechanics of space ship launches: F = G* (M*m)/r^2. But, Einstein's theory of relativity better explains the orbit of Mercury, and the observed bending of starlight around the sun during a solar eclipse, both of which have small discrepancies that are about twice what we would expect from Newtonian mechanics and gravitation. It also “naturally” predicted the expansion of the universe (though Einstein didn't realise that his was a key insight at the time, and introduced a fudge factor to get the expansion to go away). At length, thanks to Hubble et al, we see that the expansion is real, and the fudge factor has returned as a measure of the “yeast-bubbling,” universe spreading term in the expansion of the cosmos.

So, step by step, we see the generic, broad-brush scientific method in action (and some of its limitations). The basic method was aptly summarised by Newton himself in his 1704 Opticks, Query 31:

As in Mathematicks, so in Natural Philosophy, the Investigation of difficult Things by the Method of Analysis, ought ever to precede the Method of Composition. This Analysis consists in making Experiments and Observations, and in drawing general Conclusions from them by Induction, and admitting of no Objections against the Conclusions, but such as are taken from Experiments, or other certain Truths. For Hypotheses are not to be regarded in experimental Philosophy. And although the arguing from Experiments and Observations by Induction be no Demonstration of general Conclusions; yet it is the best way of arguing which the Nature of Things admits of, and may be looked upon as so much the stronger, by how much the Induction is more general. And if no Exception occur from Phaenomena, the Conclusion may be pronounced generally. But if at any time afterwards any Exception shall occur from Experiments, it may then begin to be pronounced with such Exceptions as occur. By this way of Analysis we may proceed from Compounds to Ingredients, and from Motions to the Forces producing them; and in general, from Effects to their Causes, and from particular Causes to more general ones, till the Argument end in the most general. This is the Method of Analysis: And the Synthesis consists in assuming the Causes discover'd, and establish'd as Principles, and by them explaining the Phaenomena proceeding from them, and proving the Explanations. [[Emphases added.]

It is noteworthy that this is the same Query in which Newton also said: 

Now by the help of [[the laws of motion], all material Things seem to have been composed of the hard and solid Particles above-mention'd, variously associated in the first Creation by the Counsel of an intelligent Agent. For it became him who created them to set them in order. And if he did so, it's unphilosophical to seek for any other Origin of the World, or to pretend that it might arise out of a Chaos by the mere Laws of Nature; though being once form'd, it may continue by those Laws for many Ages . . . .

And if natural Philosophy in all its Parts, by pursuing this Method, shall at length be perfected, the Bounds of Moral Philosophy will be also enlarged. For so far as we can know by natural Philosophy what is the first Cause, what Power he has over us, and what Benefits we receive from him, so far our Duty towards him, as well as that towards one another, will appear to us by the Light of Nature. ” [[If you are tempted to dismiss this as an afterthought imposed in old age (and to do much the same for Newton's General Scholium in Principia), with insinuations of senility hovering in the background, it would help to read here and here. HT, VJT of UD. Newton was a thoroughgoing design- evident- in- nature oriented theist from at least his prime years on, on the record of primary materials in the Newtonian corpus, and had probably always been a theist, albeit evidently not an orthodox Nicene Creed believer.]

Plainly, Newton was a design, creation oriented – and indeed, Bible- based – theistic thinker, who practised science as thinking God's creative and organising thoughts after him. He also specifically distinguished the origin of the cosmos and its components, from the ongoing operations "for many Ages," laying a foundation for the distinction between origins science and operations science studies. 

Let us briefly lay out the challenges and approaches:
1 --> We are often interested in  scientifically investigating the remote past of origins, or things in reaches of space such that we cannot directly interact with the entities and/or phenomena of interest. Or it may be inconvenient or unethical to carry out experiments based on manipulated variables and structured observations. In addition, we often encounter things such as electrons that cannot be or are very hard to directly observe,

2 --> Instead, we must observe traces of the world as it is, or with studies of the unobserved past, traces that point to the past. The methods of the statistician, and the detective investigating and making sense of circumstantial evidence and clues -- as opposed to testimony --  are therefore of considerable help here.

3 --> That is we are carrying out an exercise in inference to the best, empirically grounded explanation. (Often, termed abduction; a species of inductive reasoning. Induction, here, being understood in the modern sense -- arguments where the premises or empirical [[observed] evidence introduced make the conclusion more likely to be true rather than certainly so. [[For a first level look, cf here, for a serious academic discussion, here.])

 4 --> In simple essence, we are looking at facts F1, F2, . . . Fn. Such may be puzzling, but if an explanation E1 is put forth, it makes good sense of them -- ties them together in a plausible, reasonable and coherent pattern, entails them, etc. Similarly, we may have E2, E3, . . . Em, as other alternatives. But if of these some Ek makes best sense, in accounting for the facts, is choherent and harmonious, is elegantly simple and powerful not an ad hoc patchwork, then we may be entitled to conclude that Ek is the best current explanation.

5 --> Also, Ek will often predict further observations not yet made P1, P2, . . Pr. As these are ticked off through further investigations, we gain confidence that Ek is reliable and may eventually accept it as a part of the body of accepted theory in science, or as sufficiently certain that it would be irresponsible not to act on it in general life. This we can represent as a diagram that illustrates how a new theoretical explanation emerges and how it may interact with the body of accepted theory [BOAT]:

6 --> However, Ek and BOAT alike are always provisional, subject to the abstract possibility of errors. Hopefully, relatively minor corrections, but in some cases, they may need to be replaced -- perhaps even transforming our view of both science and the world. 

7 --> Indeed, in science that is what happens in a scientific revolution. Physics, the senior natural science, had a revolution across the 1600's led by men such as Brahe, Kepler, Galileo and Newton, and another one between 1880 and 1930, with men such as Planck and Einstein as the pivotal leaders. (It is no accident that our term for such dramatic changes is a "revolution," that comes form our realising that the earth revolves around the sun, and not the other way around.)

8 --> In our day, design thinkers point out that functionally specific complex orgasnisation and/or information (FSCO/I) is a major feature of the world of life, such as in the living cell:

. . . with DNA storing coded digital information that is transcribed to mRNA and then edited and sent out to ribosomes to be used in assembling new proteins (the workhorse molecules of the living cell), showing a molecular nanotechnology numerically controlled machine in action:

9 --> Where also, the only observed cause of such FSCO/I (such as in the text of pages of this course) is design, a true cause. 

10 --> So, the inference to design through the explanatory filter:

. . . is offered as the best current explanation of such FSCO/I as we see int eh living cell, which is at once potentially revolutionary.  

11 --> No wonder it is controversial in a day where it is often assumed or asserted that the only acceptable scientific explanations are those that explain based on "natural causes," i.e. those tracing to (i) blind chance processes similar to what happens when fair dice tumble and settle, and/or to (ii) the sort of mechanical necessity that would make the dice reliably fall to the table when they are dropped.  

12 --> While it is a commonplace to see such an inference to design derided as an inference to the (suspect) "supernatural, actually, it is a well-understood, longstanding inference on evidence, between (a) the natural [[= blind chance and/or blind mechanical necessity] and (b) the ART-ificial, i.e. designed. With the further point being made, that there are observable, reliable traces of design such as FSCO/I in the body of evidences relevant to the origins of the world of life. 

13 --> A point that is backed up by the fact that such FSCO/I has only one actually observed true cause, design.

Nor is this something new in the annals of science. 

Design inferences are a commonplace, and in fact, in pivotal works of modern science, there are even design inferences that point to God as author of the world. With serious implications for worldviews and for ethics. This is not just armchair speculation.
For instance, in both of his major scientific works, Newton highlighted that inferring to “the counsel” of an “an intelligent Agent” [[Opticks, Query 31] or “an intelligent and powerful Being” [[Principia, General Scholium] as the source and foundation of the cosmos has significant moral implication, as does the opposite view: holding that the complex, organised world is the product of “a Chaos” of chance circumstances and forces/laws of mechanical necessity. 

In that context, he saw that it is not only legitimate but important to address worldview foundation issues (which are freighted with implications for how we govern ourselves and develop our civilisation) in the context of addressing origins on the evidence of science. 

In short, we have most excellent precedent for an integrated overview of origins science and associated issues!

Updating the language and simplifying how Newton described the generic methods of modern science, we may use the acronym, O, HI PET:

OObservations (as accurate as we can get) are the anchor for science, allowing us to spot patterns, make measurements and test explanations.

HHypotheses (educated guesses) are made to explain the patterns we observe, and are then compared to see which is the best current explanation.

I, PInference and Prediction (based on logic and mathematics) allow us to see the expected consequences of hypotheses in new situations.

ETEmpirical Tests (though experiments we set up and carry out, and/or further observations we make in new situations) allow us to compare hypotheses to see which is best supported, and so choose the best explanations. Bodies of more or less well-supported explanations form scientific models and theories. Such models and theories always have strengths, limitations and weaknesses, so scientific research is an ongoing exercise.

Of course, as “best current explanation” implies [[and as Newton emphasised], scientific knowledge claims are provisional, subject to correction and development, or even replacement based on further work. This comes out repeatedly in the survey above, as we see how new work repeatedly partly builds on and partly corrects or replaces old thought.

When one carries out a scientific investigation, then s/he first needs to clarify what s/he is trying to do, in light of the classic sequence of scientific work: describe, explain, predict, control. Typically, one may try to:
  1. explore, observe and accurately describe or measure facts or quantities, or
  2. explain observed patterns and test the reliability of such models, or
  3. use the ability to predict to influence or control the way a situation plays out
This naturally leads to the design of an investigation. Exploratory exercises focus on getting a balanced, accurate view of what is “there,” and so emphasise fieldwork and recording of accurate facts and measurements where measurement is possible. Explanatory hypotheses or models that show patterns and perhaps the driving forces that cause them may be suggested based on “known” observations and measurements, and techniques for testing them may be recommended for “further work.” Experiments or observation studies may be designed and carried out, to test such models against further real world observations and measurements. Once an empirically reliable model – one that accurately predicts outcomes in new situations -- has been developed, it can be used to set up and control further situations. But, always, it remains provisional.

In reporting on and presenting such investigations, one useful format or sequence is:

Abstract & List of Key Words
Background Theory and Rationale (identifying issues to be explored, how, and why):
Apparatus used and Diagram of set-up:
Procedure carried out:
Results (observations, measurements, tables):
Analysis, graphs and calculations:
Discussion of findings:
Conclusions & Recommendations:

(NB: It helps to use a lab or field work book, and to lay out the report in rough form at least before hand, up to results, graphs, tables. In some cases, especially where significant, novel results are discovered, it may be wise to have results witnessed, dated and attested by a competent independent party. Lab or field notebooks have played a decisive role in more than one patent suit.)

B] Complementary interdisciplinary research techniques:

Scientific investigation are a benchmark for research, but the methods used in scientific work overlap considerably with other serious types of investigation. This is doubly so when we are carrying out origins studies.

For example, when it is said that scientific hypotheses are compared to see which is the best current explanation, this is actually an exercise in the logic of explanation and in the warranting of knowledge claims. That is, in philosophy. Similarly, the credibility of records is an issue, and that raises similar questions to those that forensic and historical investigators pursue in the courtroom or in archive rooms. And, mathematical and statistical methods are relevant.

In cases where people speak as witnesses, or where we look at the records of such testimony, the cross-examination techniques of the trial lawyer, and the evaluatory rules of thumb worked out by judges over centuries are also relevant. For instance, we must accept that it is normal for truthful witnesses to agree on main points but disagree on minor points, sometimes dramatically. Sometimes, that is a matter of noticing different true aspects of an event, but sometimes, the contradiction is all too real, and may be undecidable; apart from assessing the general and specific credibility of the witnesses. (And, given that scientific theories are always provisional, one should be careful indeed about rejecting out of hand testimony from competent witnesses that does not line up neatly with the present scientific view. For, down that road lies closed-mindedness.)

All too soon, for many reasons records become incomplete, garbled and original data may be lost; as has apparently happened with a great deal of climate related weather data. Worse, scientific computer programs are notoriously poorly documented, and the logic of the algorithms used to process data may be even more open to question than the data itself. In such cases, the names of claimed original sources, chain of custody and general quality of accessible copies may be all we have access to and must use. (But, quite often that is good enough; except where the matters in question are highly controversial. Which often happens on origins science matters.)

This set of considerations fits in with the background and rationale element of a formal experiment or observational study report as outlined above, but sometimes the exercise is sufficiently elaborate to do on its own, as a balanced Critical Review study, often leading to a novel contribution (often, a bit of logically or mathematically based theoretical analysis), and a Statement of Findings and then Recommendations:

Abstract & List of Key Words
Aims (or, for a course unit: desired learning outcomes):
Background and Rationale (prior work, the state of the art, concepts, schools of thought and key issues):
Major techniques and examples (strengths and limitations):
Assessment and problem to be addressed (i.e. your proposed work):
Procedures and Results (your actual work):
Discussion of findings (analysis based on your work):
Conclusions & Recommendations:
Bibliography (sometimes “further reading”)

(NB: This approach also fits well with the needs of an educational unit, especially where the subject matter is controversial.)

C] Setting up & Carrying out a research study:

In effect, an independent study – whether fieldwork based or library research and/or analysis based -- is a minor exercise in project management. As such, the initial idea will have to be developed, a proposal may have to be written to obtain permission, mentoring/ sponsorship/ supervision and perhaps funding; and the actual investigation and reports will have to account for what was done and the way resources were used.

A possible format for such a proposal is:

Timeline Chart
Background & Rationale (justification for doing the study)
Goals, Objectives, Implementation Stages & Steps
Deliverable Results (at milestones)
Inputs (people, skills, materials, equipment, facilities, time etc)
Budget (estimate of financial costs & sources)
Expected Outcomes, Benefits and Impacts
Requested Assistance
Concluding Remarks

Once you have the support and resources required, the timeline and budget are maybe the most useful tools to help guide and control the implementation. Not far behind is a lab or fieldwork notebook (or a journal of activities if you are not doing an empirical investigation science project). Regular meetings that allow you to report on progress and challenges, with opportunity for suggested ways to overcome the latter, will be very helpful.

D] Reporting, Displaying and presenting findings fairly and effectively

In addition to the sort of formal report in a standard format (e.g. as shown above), you will as a rule have to make a report in person to a panel or to the public, and may have to justify your conclusions. In addition, you may need to prepare a poster [[often, based on the abstract, but with key illustrations or pictures] or a display, or a multimedia slide presentation. Sometimes, you will have to do all four.

The best place to begin is with the abstract which already is a summary of up to 250 or so words.

To make up a poster or panel of posters, pick out what you need to highlight, and what pictures, charts, graphs etc will best make your point. (Nowadays, multimedia presentation software will have a poster mode that will be helpful. Just remember the rule: for every 30 feet of distance of the audience you will want an inch/ 25 mm of text size. So, to attract attention from a doorway about 50 feet away, you may want to start with two-inch text (and more if you can get it), making judicious use of colour. Then, since you can expect to have people approaching the poster within a dozen feet or so, ½ inch or a bit bigger text in an easy- to- read font will probably work for general information.

But, remember, too much text will rapidly lose audience focus, if you are dealing with the general public. (A tri-fold letter size sheet brochure is a useful back-up, and then it helps to have a web page or Wiki or blog Internet address for more details and a copy of the full report. Contact information will help too, not only on the brochure but on a business card.)

Often, the best way to do a display is to have a poster or panel of posters as a backdrop, and to have the physical items on a table in front of these posters.

For a multimedia presentation, break up the main points into slides, and copiously illustrate with pictures, graphics, and -- if you can do so -- short video clips or the like. Avoid too much text on a slide, though you should not shun to use words, if you need to give a crucial citation or the like. Make sure you know how much time you are expected to present for, and how much time you will have to leave for questions. A one-sheet, letter size handout is often helpful, and if it is written up like a magazine article with three columns and a picture or two, with key graphics, that may be helpful.

Again, it helps to have a web site reference for follow up.

The real challenge with such a presentation, poster or display is to make sure that findings are reported clearly, fairly and effectively. The secret to this is to make effective use of the background and rationale section of the report, summarising the key facts, concepts, issues, and schools of thought with their strengths and limitations. Then, you can showcase why you are did your work, and how it improves on the state of the art. Finally, present your findings and conclusions, with suggestions for onward work.

It may be useful to footnote references in a smaller font, and if they are online, it may be useful to make the links active, so that if questioned you can go directly to the source.

The effectiveness of the presentation then grows out of its fairness, substance and the evident quality of work put in.

Finally, a word or two on criticism. If your strongest critics are addressing substantial issues and are highlighting evident gaps in your reasoning, thank them; for they have helped you advance to that which is sound. If instead they are going off on tangents, distorting or taking out of context, then trying to belittle, embarrass or ridicule you, that is a sign that your work is fundamentally sound; so, take heart.