Example:The Effect of Indentation on Program Comprehension

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• 2.2 ???????
• 2.3 ???????
• 2.4 ????????
• 2.5 ??????????

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2.1 ???????

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ExampleThe Effect of Indentation on Program
Comprehension

• ???????
• Managers of data-processing centers and other
  organizations often find it practical to
  establish standards regarding the format of
  computer programs. The use of programming
  standards may make programs easier to comprehend
  and thus may enhance programmer productivity. In
  recent years, a variety of standards have been
  proposed in the literature. Yet often these
  proposals are offered with no more foundation
  than the experiences of a small number of
  professionals. To be effective, programming
  standards must be based on empirical ????(??)?
  data concerning program comprehension and the
  factors that affect it.

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• ???????
• A number of researchers have begun to collect
  empirical evidence regarding the effects of
  various factors on program comprehension.
  Woodfield et al. (1981) investigated
  modularization and comments and found that
  subjects given programs containing comments were
  able to answer more questions correctly about the
  program than those who did not have comments and
  that subjects given an abstract data type version
  of the program could answer more questions
  correctly than those given any of three other
  types of modularization. Sheppard et al. (1979)
  studied the effect of structured coding and
  mnemonic ????? variable names on program
  comprehension. They found that unstructured
  programs were the most difficult to reconstruct
  and that there were no differences in program
  comprehension among the levels of variable
  mnemonicity.

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• Shneiderman (1976) compared the logical and
  arithmetic IF statements of Fortran and found
  modest ??? support for the hypothesis that
  beginning programmers tend to find the logical IF
  easier than the arithmetic IF, whereas
  experienced programmers find them equally
  difficult. Green (1977) investigated nested and
  jumping-styled forms of the conditional statement
  in the context of two typical programming tasks
  tracing and reporting the truth-conditions needed
  to reach a point in the program. He found that
  both tasks took longer when the program
  conditionals were written in the jump form.

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• ???????
• Although these studies have provided much
  valuable information on the relationship between
  various factors and program comprehension, there
  are still many factors that have not yet been
  explored.

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• ???????
• This paper describes an empirical study that
  investigated the effect of indentation on program
  comprehension. We tested three different
  indentation styles for the same program control
  structures no indentation, moderate indentation,
  and excessive indentation.

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• ???????
• The results of this study may be of interest to
  managers and educators attempting to develop
  programming standards and to researchers
  interested in the psychological ??? aspects of
  computer programming.

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2.2 ???????

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Example

• 1st?????programming behavior 1As research into
  human factors in software development continues,
  it has become important to develop a detailed
  cognitive ??? model of programming
  behavior.2nd 3rd?????comprehension 2One of
  the major components of programming behavior is
  comprehension. 3Comprehension is involved in
  nearly all aspects of programming work, including
  writing, debugging, and modifying software. 4th
  5th?????psychological complexity 4Thus
  factors that relate to program comprehension must
  be explored. 5One of these factors is
  psychological complexity, which one expert has
  defined as "characteristics that make it
  difficult for humans to understand software.

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• 1st?????
• programming behavior
• 2nd 3rd?????
• comprehension
• 4th5th?????
• psychological complexity

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Example

• As research into human factors in software
  development continues, it has become important to
  develop a detailed cognitive model of programming
  behavior. One of the major components of
  programming behavior is comprehension.
  Comprehension is involved in nearly all aspects
  of programming work, including writing,
  debugging, and modifying software. Thus factors
  that relate to program comprehension must be
  explored. One of these factors is psychological
  complexity, which one expert has defined as
  characteristics that make it difficult for
  humans to understand software.

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Example ?????

• Managers of data-processing centers often find it
  practical to establish programming standards. 
• Comprehension is involved in nearly all aspects
  of programming work, including writing,
  debugging, and modifying software.
• The use of programming standards may make
  programs easier to comprehend.

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Example ?????

• As the standard of living has improved in the
  last ten years, beer, a Western beverage, has
  become very popular in China.
• In recent years, a variety of standards have been
  proposed in the literature.

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2.3 ???????

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• Type I ?????
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ExampleWheat Residue Loss from Soil Surface
under No-till ?? Management

• Several laboratory studies have been conducted to
  determine actual decomposition ??,?? rates of
  wheat ?? and other small grain ?? straws ??
  -using 14C-labeled plant material. Martin et al.
  (1980), using optimal conditions of -33 kPa water
  potential and 23C, determined that 74 of the
  carbon in wheat straw evolved into the atmosphere
  as CO2 after 2 years. A companion study showed
  that after 1 year the 14C from wheat straw that
  had not evolved as CO2 could be accounted for
  ?? in the soil ?? microbial ??? biomass
  ??? (Stott et al., 1983).

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• Most field studies ???? have used straw-filled
  cloth or fiberglass ???? bags buried in soil,
  and decomposition has been measured as weight
  loss. Smith and Douglas (1968) noted an average
  44 weight loss in 12 weeks from buried wheat
  straw. In another study, weight loss from straw
  of 23 varieties of small grains ranged from 54
  to 75 after 1 year (Smith and Peckenpaugh, 1986).

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• Few studies have been done on surface-residue
  ??? loss. Brown and Dickey (1970) used
  fiberglass bags to compare decomposition rates of
  buried straw and straw left on the soil surface.
  Over 1.5 years, surface straw disappeared at
  one-third the rate of buried straw. A study by
  Douglas et al. (1980) showed similar results
  after 2 years.

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• Type II ????
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ExampleWind Pressures on Buildings with Mullions
??????

• The effect of mullions ?? on wind pressures on
  buildings has not been extensively examined.
  Hoerner (1957) discussed the effects of vertical
  ribs ????? on a circular cylindrical storage
  tank ???????? and reported that the suction
  ???? peaks are eliminated by ribs on the
  outside structure of the storage tank. The drag
  ?,?, however, is higher on a cylinder with ribs
  than on a tank with a smooth surface. Leutheusser
  (1970) performed a series of wind tunnel ??
  studies on building models with various
  architectural details, including mullions. Other
  than very local effects of wind-induced pressures
  between mullions, the overall trend for most
  regions showed no difference between the cases
  with and without mullions.

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• Roshko (1970) also carried out tests on circular
  and prismatic ??? cylinders in an aeronautical
  wind tunnel and discussed the effect of surface
  roughness modeled by mullion-like grooves
  ??,??. He reported that the pressure
  distribution depended on the Reynolds number
  (???????)???.

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• The effect of the Reynolds number was also
  discussed by Standen et al. (1971), who attempted
  pressure measurements on a full-scale building
  with mullions, as well as on a wind tunnel model
  of the building. They deduced that the scale of
  the mullions should be proportional to the local
  boundary-layer thickness. Templin and Cermak
  (1976) carried out full-scale and wind tunnel
  studies concerning the effect of mullions on
  wind-induced loads on buildings and found that
  the mullions reduced the magnitude of the mean
  and RMS pressures on the sides of the building on
  which the main flow reattached after separating
  from the upwind ??? corner. Finally, Leadon and
  Kownacki (1979) discussed fluctuating pressures
  generated by I-shaped external mullions on a
  curtain wall in a two-dimensional flow.

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• Type III ???????????
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ExampleBack Pain and Exposure to Whole Body
Vibration in Helicopter Pilots ??????

• In several epidemiological ????,????? studies
  on back pain in helicopter pilots, a distinction
  has been made between transient ??? back pain
  and chronic ??? back pain (Shanahan et al.,
  1986 Froom et al., 1986). According to Bowden
  (1987), chronic back pain might be compared to
  idiopathic ??? low back pain in the general
  population. Back pain prevalences ?? in
  helicopter pilots reported by several authors
  vary from 21 to 95 (Schulte-Wintrop and Knoche
  1978 Fischer et al. 1980 Delahay et al., 1982).
  The prevalence of back pain during or shortly
  after flight ranges from 34 to 64. Back pain not
  primarily associated with flight is reported in
  11 to 27 of the respondents (Shanahan et al.,
  1986 Froom et al, 1986)....

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• A number of experimental studies have also been
  conducted. In a mock-up ???(??)?? of a UH-1H
  helicopter seat and control configurations, 11
  subjects were asked to adopt ?? the posture
  ?? they assumed in normal flight and were
  tested for two separate periods of 120 min, one
  with simulated helicopter vibration and one
  without (Shanahan and Reading, 1984). No
  significant difference was found between the
  vibration and non-vibration conditions for either
  time of onset ??,?? or intensity ?? of pain.
  Pope et al. (1986) tested the change in muscle
  response due to sustained ?? posture and
  vibration in a simulated UH-1H cockpit ??.
  Marginally significant fatigue ?? occurred only
  as a result of the sustained static posture. In
  contrast, all tests both with and without
  vibration produced discomfort in the lower back.

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• Froom et al. (1987) compared the onset and
  intensity of back pain between aviators ???
  occupying the pilots seat and the gunners ??
  seat of a helicopter. Most pilots experienced
  pain or discomfort in both positions. However,
  the intensity was greater and the onset of the
  pain quicker in the pilot's seat....

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2.4 ????????

• 2.4.1 ??????
• 2.4.2 ??????
• 2.4.3 ???????
• 2.4.4 ??????

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2.4.1 ??????

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• Example(James, 1985)
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• Example(1,2,4)

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Example ?????
crop??,decompose??,??
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Example ?????
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Example ???
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2.4.2 ??????

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Boron?,Doping??,Prevalence??
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• ExSeveral studies have been done on X.
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• Few studies have been done on Y.
• Little research has been done on Y.

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• several writers
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2.4.4 ??????

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• 2.5.1 ???????????
• 2.5.2 ????????????????
• 2.5.3 ????????????????
• 2.5.4 ????????

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2.5.1 ???????????

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Gravity??,Moon??,Orbit????
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2.5.2 ????????????????

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2.5.3 ????????????????

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2.5.4 ????????

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• ????,??????????????????
• Rogers (1982) performed the first systematic
  study of this illness. His data provided the
  starting point for many later investigations.
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• Smith (1978) presented a method for solving
  problems of this form when x?1. However, his
  method is not applicable to the general case. 
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• Smith (1978) presented a method for solving
  problems of this form when x?1. However, his
  method was not applicable to the general case.
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