Beach Haven

Latour, Bruno, and Steve Woolgar. 1979 & 1986. Laboratory Life: The Construction of Scientific Facts. Princeton: Princeton University Press.
 
Review by Michael Beach

​This work examines one of the large questions in the field of Science, Technology, and Society (STS). Are scientific facts discovered, or constructed? For the authors, facts are constructed.

Among the ideas of this work, Bruno Latour and Steve Woolgar describe reducing disorder in data as lowering noise, or increasing the signal-to-noise ratio (S/N) between data that support a specific hypothesis, and those that don’t. Data that don’t support a hypothesis are not necessarily counter-finding data, they are just not supporting data, hence noise. This is a concept I am very familiar with from my work in satellite and broadcast networking. It also directly relates to the authors’ concept of inscription. When data are created through process, the result is inscription. As theories become accepted they tend to change into tools to further test new theories. Tools can be physical machines or processes. When the machine or process become normalized they are said to be 'black boxed'. Such black boxes are no longer questioned, but are simply accepted. In labs, the machines (black boxes) referred to take information in and spit out printed material (data sheets or curves). It is the interpretation of data or curves that come to represent what matters in the argument for one idea over another. The more isolated one point of data is over others, the more distinct the information (higher S/N), and the more it supports a specific idea.
 
There are lots of steps along the way in the machine input, processing, printing, and transcribing of data into descriptive curves. Part of the work’s argument is that without all the manipulation a distinctive curve would not result. It is just as likely, the author’s say, that another set of complex manipulations could lead to a completely different looking curve, and a different conclusion. This is especially true if earlier curves had led to a different machine (black box) to process data in a different way.
 
My satellite and broadcast example includes the use of two tools. One is called a spectrum analyzer (SA), the other is called an integrated receiver decoder (IRD). Anyone who has ever worked with satellite or broadcast signals is familiar with these tools. In satellite, for example, after a transmit earth station (uplink) sends a signal to the satellite, and the satellite receives and sends the signal back to earth to a receive earth station (downlink), signal parameters can be both displayed by the SA, and made sense of by the IRD. Both machines have complex electronic systems within them. For example, the IRD has to first demodulate the radio frequency (RF) energy, then decrypt the data stream, then decode the information within the data stream, then transform the information into something a human can understand (audio, video, text). The SA similarly requires many parameter adjustments until the energy sent through the air can be displayed and measured in a standard format, typically comparing energy density levels at given frequencies (instantaneous or averaged over some period of time). Without all that effort the information does not really exist from the perspective of Latour and Woolgar. In fact, without the equipment, intelligence (audio, video, text) would simply be lost in space.
 
I’m reminded of basic communications theory. In order for communication to happen someone must have an idea, encode it (i.e. speech), and send it across a medium. The requirement does not stop there. Someone else must perceive the signal within the medium, and have the knowledge required to decode the information (shared language and context). Does the knowledge actually exist before all those communication steps are taken? Many in the field of STS would argue that knowledge not shared is not really knowledge. Chapter 5 of Laboratory Life emphasizes the need for a form credit in order to incentivize scientists to share or communicate findings, which in turn causes knowledge creation. This idea doesn't seem to sit well with Robert K. Merton's scientific norms, but are more akin to Ian I. Mitroff's counter-norms. Because of all the required inscription effort, the authors (Latour and Woolgar) argue that such knowledge is constructed rather than discovered.
 
Below is a typical SA plot. The square shape in the middle is the desired signal. The somewhat horizontally flat lines at either side are a representative measurement of the “noise floor”. There is never an absence of noise as radio frequency (RF) energy is always present everywhere. It is generated by the sun and many man-made devices. To obtain the S/N ratio is a simple comparison of the power measurement at a representative (average) frequency at the top of the desired signal as compared to power as measured at a representative (average) place in the noise floor. The two are then divided into a ratio. Depending on the sensitivity rating of the IRD in use, there is a minimum desired threshold. All measurements are in a decibel (dB) scale. Note the specificity of the measurement scales, as well as several 'settings' in the bottom right corner required to construct the graph. All of these scales and settings are adjustable within the black box of a spectrum analyzer. To Latour and Woolgar's point, changes in scales or settings (or principles and processes leading to creation of the SA) would yield data depicted differently on the plot.

Mavhunga, Clapperton Chakanetsa. 2018. The Mobile Workshop: The Tsetse Fly and African Knowledge Production. Cambridge and London: The MIT Press.

Review by Michael Beach

Among many threads, Mavhunga makes a point around ‘thingamication’. He shares examples throughout the book on colonial (and later) white perspective on African people as objects of study, control, labor, and information.

One striking example was the use of fences in building corridors through tsetse infested areas. Local labor was used alongside a thing called a bulldozer to clear forest where the land was too steep for the machine. They were also used to put in fencing, then funneled through those fences and ‘de-flying’ stations while moving along the fenced paths (182). The roads themselves were also a product of African labor, mostly built to allow for traffic between white-owned farms as well as for Africans to get from their homes to work in mines or on farms. These same Africans were able to move through traditional paths in ways that avoided infested areas during infested times before the belief that roads and fences were necessary.

Another particularly difficult approach from the perspective of Mavhunga was government creation of villages as a prophylactic. This effort removed people from their ancestral homes to gather them in new communities in between white-owned farms. Clearing and building up these small towns forced elimination of tsetse habitat (as well as habitat for nature in general), lowering the threat to sparse white-owned farms. The towns became a form of human shield. This approach lead to overcrowding of people in the buffer zones, and over burdening of the soils around the new towns (153). Mavhunga gives examples of eventual movement patterns adopted by officials that were not all that different than those previously employed by locals, but instead of preventative movement efforts these were about damage control (161).
​
I’ll share one more human-as-object example. When authorities added chemical efforts to ‘mechanized phytocides’ (141) Africans again became a tool for the effort. While pilots sprayed less effectually from the thing called an airplane, African workers called ‘spray boys’ were given backpack pneumatic sprayers to go directly into the infestation. This put them as risk both from the fly and from the chemical poisons. Mavhunga offers a great deal of insight over several chapters about which chemicals were used during various periods and the effect on the fly, the plants, the environment, wildlife, and humans who both applied the poison and lived on the affected land. Decision makers only backed off aggressive use of chemicals when whites in the area began to complain after the shift from organic to synthetic pesticides (152).

​BLACK INVENTORS IN THE AGE OF SEGREGATION
By Rayvon Fouché
The Johns Hopkins University Press, 2003, 225 pages
Review by Michael Beach
 
In this work the author shares the personal stories of three specific African American inventors in attempt to call into question several myths often perpetuated about black technologists. The ideas are how a patent equals financial success, people of color invent purely to uplift the race, or that Black-patented objects are the first of their kind. Fouché approaches these myths by building a narrative about each of three inventors that contradict one or more of them. The inventors are Granville T. Woods, Lewis H. Latimer, and Shelby J. Davidson.
 
This approach by Fouché goes a long way to dispel the inventor-as-hero narrative which has been put in question by other writers about other inventors without the race angle included. In this work race is certainly part of the narrative, but not exclusively the narrative, making the complexity of both the inventors and others they interact with more nuanced, and enlightening. Fouché approaches this historical and sociological work in this way in order to show three different people with three different personalities, cultures and motivations. In other words, they are each a unique person and not some sort of imagined icon.
 
The work would appeal to those with interest in technology, sociology, racial studies, and history. Fouché connects with readers through clear language, personal stories of the three inventors, depicting and dispelling ideas commonly held in both the African American and majority communities. The strength of the work comes through the individual lives depicted, and how these men fit into larger societies. They are juxtaposed to other prominent Black leaders that they were at odds with. Their histories do show how they were at times helped by race, and at times hamstrung. Perhaps a deeper look at societal trends that inspired the inventor-as-hero myth, and in particular the black-inventor-as-hero myth may have add more insight into Fouché’s main argument. One could argue, given the documented experiences, how the effects of these inventors’ efforts perpetuated these beliefs at least at some level, and were not just debunking.

LEVIATHAN AND THE AIR-PUMP
HOBBES, BOYLE, AND THE EXPERIMENTAL LIFE
By Steven Shapin and Simon Schaffer
Princeton University Press, 1985, 391 pages
Review by Michael Beach

This history covers an important time in the history of scientific thought. Many scholars consider the 17th century as the ‘scientific revolution’. Many famous discoveries took place around this time. The history under review here speaks to a major debate of the time. Represented by Robert Boyle were those who believed in experimentation as the basis of knowledge production. Thomas Hobbes, on the other hand, questioned experimentation, preferring philosophical debate as the basis for coming to understanding. Boyle argued that we should believe our eyes, yet so much of experimentation is ‘managed’ that even today debate over knowledge construction versus knowledge discovery continues.
 
The reading claims that “many aspects of the programme that he (Boyle) recommended continue to characterize modern scientific activity and philosophies of scientific method” (p. 341).  Yet the pump experiments varied in both makeup and outcome. Theories also varied from pump to pump and outcome to outcome. Did facts created by experiments explain the various theories, or did the various theories serve to explain the facts noted in the experiments? When one interprets facts, are they interpreting whether something is a fact, or are they interpreting the meaning of the fact itself?
 
There also seems to be an interesting power balance issue. Hobbes had a connection with the king. You’d think that would have caused his arguments to carry more weight. Yet Hobbes was not accepted into The Royal Society (a prominent British scientific association). The authors offered a long set of examples of speculation by others as to why that was.  Some of the arguments surrounded Hobbes’ personality, yet Shapin and Schaffer show how some accepted members were perhaps more surly than Hobbes.
 
It may have come down to the fact that Boyle had members of The Royal Society act as witnesses to his air-pump experiments and even sign affidavits to the effect. At the same time Hobbes questioned the need for repeated experiments, or at times any experiments. By questioning the intellectual approach of the use of ingenuity (p. 130), which for Hobbes and his detractors was understood to be a slant, he put himself at odds with what amounted to be much of the collective thought leadership at the time. Reliance on the mechanical ‘tricks’, as he put it, was to denote something less than true philosophy.
 
Hobbes wrote a treatise on knowledge and science published in 1651 which he titled Leviathan. Aside from Hobbes’ negative portrait of experimentalists, most members of the Society looked at Hobbes as too dogmatic, including this publishing.
 
Whatever one believes to be the ultimate issue, the authors clearly state, “The rationalistic production of knowledge threatened that involved in the Royal Society’s experimentalism” (p. 139). Hobbes made an interesting assertion that many would still argue today. He depicted Boyle’s experiments as being based on his own assumptions about the nature of air. Likewise, it’s clear that Hobbes also had preconceived ideas. In fact, both Boyle and Hobbes came to what today would be thought of as false conclusions about what was happening inside the vacuum created by the pump. One could argue Boyle pre-decided the outcome of the experiments, the matters of fact, based on his ideas around the nature of air. Likewise, Hobbes essentially argued to ignore the experiments since the interpretation of the outcome was not proven, only conjectured. Yet Hobbes put more stock in his own ideas without any consideration of any matters of fact. As I see it both were socially constructing their perceptions pre- and post-experimentation.

SPACESHIP IN THE DESERT
ENERGY, CLIMATE CHANGE, AND URBAN DESIGN IN ABU DHABI
By Gökçe Günel
Duke University Press, 2019, 256 pages
Reviewed by Michael Beach

Success or Failure?


This book recounts the history of an entire community created in the deserts of Abu Dhabi based on renewable energy approaches. The idea was to create a campus in which new energy technologies could develop to help the country become less dependent on petroleum revenue. The name of the new city is Masdar.

Günel notes how Bruno Latour referred to technology as a system (p.139). Where most of us see only the portion we interact with, that portion is supported by an entire network of interconnected parts. For example, at Masdar people in general noted the pod cars of the Personal Rapid Transit (PRT) system as if they were one and the same (p.142). In fact, the pod cars are of no worth without the supporting system known as the undercroft, the controlling software, and an army of maintenance crew, often made up of workers from Asia. These workers were not allowed to live in the city, nor even use the pod cars once up and running.


How does one describe project success or failure? Exactly! The fact that this is even a question points to how criteria (official and unofficial) varies with every beholder’s eye. 


The PRT was not successful in that it could not handle large numbers of passengers efficiently. It was not cost effective. The undercroft requirement caused increased indirect expenses for the buildings which had to be lifted by 20 feet to accommodate the required space. One could simply walk the short distance the PRT served. It went not faster than a bicycle. Eventually, when a new executive took over the Masdar facility, the PRT was cancelled.


Despite the pessimistic view, others saw how people who came to visit the facility lined up to ride the PRT despite the availability of a shuttle bus during large events. Even jaded academics who pointed out issues still used the system because it was fun, making functionality a secondary consideration (p.142).


Günel makes the point of how the Masdar PRT is just one in a string of PRT projects that all end essentially the same. Although the system in West Virginia is still in use, it does so with a $120M price tag and an annual cost of $5M, and has stayed essentially small scale. It only goes between  West Virginia University (WVU) campuses and downtown Morgantown. 


In his 1994 book  The Anti-Politics Machine: “Development,” Depoliticization, and Bureaucratic Power in Lesotho, Jame Ferguson argues whether or not original project goals are realized, something is accomplished. The project goals represent an entry point of development efforts, but whatever effect comes about, stakeholders think of some outcomes as desirable, and others as undesirable. 

THE SYNTHETIC AGE
OUTDESIGNING EVOLUTION, RESURRECTING SPECIES, AND REENGINEERING OUR WORLD
By Christopher J. Preston
The MIT Press, 2018, 195 pages
Reviewed by Michael Beach

The Singularity

Among the many threads in The Synthetic Age, Christopher Preston refers to a book by Ray Kurzweil. In The Singularity is Near, Kurzweil defines this event as when artificial intelligence (AI) gets ahead of human intellect. Preston characterizes results of this theoretical event as “a future in which artificially intelligent machines gain a runaway intellect that exceeds anything the human brain can counter” (157).

This theme is a common thread for Preston. Earlier in the book he expresses concerns over other synthetic proposals run amuck. Nanobots that self-replicate, biobots acting as bacteria, genetically created bacteria acting as bacteria, and unforeseen effects of approaches to cooling the earth are some of the examples Preston points to where technical solutions to natural concerns carry their own risks.

Why the ethical backlash to the idea of genetically-created humans, for instance? Dubbed the Human Genome Project 2, some organizations want to take technical lessons learned with genetic recreation of simpler life forms and apply them to the more complex genetic sequences of humans (154). The singularity of AI described by Kurzwail considers software as a servant of humanity, even if the risk of so many sci-fi movies of the machine taking over exists. Creating human life synthetically for purposes such as harvesting organs or experimentation raises reasonably grave concerns. For instance, would a genetically created human be a human? If so, then human rights would apply to them, and would preclude their use as test subjects or organ farms. If not human, then one could argue the ‘experiment’ would have failed. This ethical area hearkens back to Mary Shelley’s Frankenstein.

One of Preston’s base arguments shows how concern over human interference with nature is not avoidable. In fact, humans have always interfered with nature. Preston points out how some argue that humans are a product of nature so human acts are acts of nature. The difference between human acts and natural acts gets blurry when humans intervene in natural processes as simple as moving butterflies north in England to help them migrate fast enough to avoid perceived global warming effects, or as complicated as seeding sulfuric acid in the stratosphere to lower sunlight penetration. Human history and natural history begin to merge (149).

DEMOCRATIC DESIGNS
INTERNATIONAL INTERVENTION AND ELECTORAL PRACTICES IN POSTWAR BOSNIA-HERZEGOVINA
By Kimberley Coles
University of Michigan, 2007, 297 pages
Review by Michael Beach

Democracy is neither natural nor intuitive (5)

For those of us who lived our entire life in a country based on democratic principles, the idea that democracy would be thought of as unnatural and counter intuitive seems itself to be counter intuitive. Coles makes a compelling case when one considers all the thought and effort it takes to create an election. An election is really three separate processes, voter registration, voting, and results tabulating. All are complex. Each are made up of many actants (people, objects, processes).

Parts of the international community have a fundamental belief of democratic society as the best power to bring about peace (237). Bosnia-Herzegovina seemed to outsiders as somewhere that could be improved through the imposition of democratic principles since in the 1990s it suffered from war, authoritarianism, and communism (33).

Coles argues rather convincingly how the need to create complex labor-intensive processes, and a perceived need to impose democracy through negotiation and external experts (or even internal experts) would seem to question naturalness. So many places along the election path are fraught with both innocent and intentional process ambiguities and deviations. Many options along the planning and execution paths are open to design and interpretation based on assumptions by system architects and implementers.

Since democracy was a new approach to Bosnians, fears of unfairness or interference led to a desire for transparency. This transparency was bodily symbolized in form of the (sheer, mere, peer) presence of international experts (88). This is similar to the point made by Rist about the need for technical measures including scientific (or expert) knowledge.

Coles argues not only a need to use experts, but also how these experts are knowledgeable about processes that are used in virtually any setting using a cookie-cutter approach (16). The agencies seeking to facilitate the democracy machine approach argue that using ‘standard’ practices makes the effort apolitical or acultural (77) much as Ferguson describes. Technicality equates to depolitization (152).

The intent of holding an election is to translate voter will into political authority so long as those imposing democracy deem the outcome as desirable. The process has to be perceived as valid, but who’s perception matters? Whoever judges validity, in Coles argument the process and outcome needs to be perceived as free and fair. The election is not discretely either free and fair or not free and not fair, rather processes need to be free enough and fair enough to create confidence (155). Mathematically, that is more likely if there is some level of transparency (though total transparency is not really possible). How transparency is measured is another ambiguous concept. So long as the difference between winners and losers is well outside the margin of error perhaps there is more trust. When races are more closely contested then trust is probably more an issue.
​

​THE CULTURE OF AI
By Anthony Elliott
Routledge, 2019, 246 pages
​Review by Michael Beach
 
The work is subtitled “everyday life and the digital revolution.” Despite the futuristic robot image on the cover page, Elliott looks to more contemporary practical implications of AI, some of which may be scarier than the stuff of sci-fi movies.
 
Elliott does address robotics such as how technology and automation are growing in the workplace, along with some of the social and economic impacts of that trend. A less flattering look of ‘digital life’ is around our tendencies toward narcissism. Technology can inspire these tendencies. For example it may be more important to some to take online actions to increase follower counts, than to let go of the keyboard and have personal interaction with others. As a reviewer, I was certainly forced to ask myself the question about why I feel a need to publish a review on our family website about each book I read. So far I have resisted the temptation to similar things on other platforms, though I do have a public presence on several social media apps.
 
In the book, Elliott takes time to explore some of the potentially sinister aspects of AI such as automated so-called bot actions, surveillance, and even military applications. Concerns over stalking, bullying, and exploitation by the sex industry express how cyber and robotic tools can enhance the negative parts of humanity. He takes a look at each of these uses of AI and societal impacts as well. Despite the negatives, he gives similar space to positives such as increased capabilities in healthcare, remote communications, crime fighting, and democratic processes.
 
Technology and society are co-productive. Both are ever more mobile. Each cause the language and thought patterns of the other to evolve. Despite all the life enhancements tech and AI bring to modern life, I’m still an advocate of occasional unplugging. I believe it helps us be more human.

​THE PHILOSOPHER’S TOOLKIT
By Julian Baggini & Peter S. Fosl
Wiley-Blackwell, 2010, 284 pages
Review by Michael Beach
 
The subtitle for this work is A Compendium of Philosophical Concepts and Methods. The authors have organized philosophical ideas in a dictionary-like format. The ideas are explained, along with how philosophers tend to use each idea in practical argument. Some philosophies also accompany a short history of the given idea. The authors do not approach the discipline comprehensively, rather they narrow philosophical argument to areas associated with science and technology.
 
The reader will find the work both academic for contemplation, and practical if engaging in debate. If one studies science and technology, perspective and clarity of thought behind various approaches of areas of discipline are informed by understanding major movements in scientific thought. 

​REPRESENTING AND INTERVENING
By Ian Hacking
Cambridge University Press, 1983, 287 pages
Review by Michael Beach
 
In this work, Hacking reviews philosophical thought related to science and technology from the perspective of how scientific and technological ideas do or don’t represent reality. He also shows argument around scientific use of ideas and technology to create reality (intervening). Aside from reviewing the main arguments and philosophers involved on the topics he often interjects his own stands on the issues.
 
An example of a key philosophical debate is eluded to in a quote by Lakatos. His reading of Popper on knowledge growth stated simply is, “people propose, nature disposes” (114).
 
Hacking makes a number of comparisons between the philosophical perspectives of Lakatos and others such as Popper, Kuhn, Putnam, and Kant. The key phase is one focus, specifically on how (and if) science progresses. For Lakatos, successive research either progresses a theory, or degenerates it (117). In this way, theories are bolstered or unsupported by empiricist efforts.
 
Some direct comparison between Kuhn and Putnam allows Hacking to clarify. For instance, while Kuhn speaks of scientific revolution, Putnam is focused more on evolution in terms of knowledge growth through rationality (111). Putnam further muddies the knowledge-growth question through the concepts of reference and extension. One of his arguments, for example, is that a given reference may be understood differently by different people, making the extension, including knowledge growth though experiment, essentially impossible (101). If one accepts this premise, then proposals by people (theories) are not universally understood, nor the disposition of nature as neither the proposition nor the disposition are held in common among scientists.
 
Putnam’s struggle is with meaning. Hacking denotes that a reference is the meaning, or thing, represented by the word. Sense is more like the connotative understanding of the thing, the reference in question (75). If Putnam questions one’s ability to concur with others on either reference or sense, then his questioning of knowledge growth is understandable. The scientific world seems to get around the difference through the practice of dubbing. Where Lakatos would argue that knowledge growth can only be understood in retrospect (118), Hacking argues in favor of dubbing “new natural kinds” which are “often the result of initial speculations which are gradually articulated into theory and experiment” (82).
 
Ian Hacking’s work shows a mixed message claiming varying schools of scientific philosophy share common ground, yet differ in fundamental ways, stating how such point-by-point opposition between philosophers only means there is ‘underlying agreement’.
 
By introduction, Hacking makes a case for ‘common ground’.  He shares seven areas where he believes Carnap and Popper, and by extension philosophers of science in general, tend to agree (5). Natural science is the best rational thought. Distinction exists between observation and theory. Knowledge is cumulative. Science has a deductive structure. Science depends on precise language. Unity of science methodology exists in each discipline. Finally, the context of justification differs from the context of discovery.
 
Despite these unifying assertions, pretty much all the rest of the reading shows an evolution, along with examples of fundamental change of thought. For example, Hacking’s first positivist instinct refers to falsifiability as a ‘variant’ of verification (41), yet early in his work (3) he refers to the divided image of Carnap and Popper as betraying a ‘deeper’ difference. It seems difficult to justify such ‘deeper difference’ with simply being ‘variant’. Difference is variable, on a subjective scale. Qualifying words expose subjective opinion. At times Hacking depicts difference as minor, other times as significant.
 
Hacking describes schools of thought within his own form of structure; realism vs anti-realism, causal vs anti-causal, theoretical entities vs anti-theoretical entities, and the list continues. A specific example referred to earlier was the divided image of Carnap and Popper. Carnap was in favor of science as verifiable. By this he claimed metaphysics is not science, inductive reasoning should be employed, and there are important meanings in language. Popper, on the other hand, stood for science as falsifiable. By this he argued metaphysics leads to science, deductive reasoning should be employed, and calling meanings and language only ‘scholastic’ (4).
 
Difference can be understood subjectively by degrees. Hacking seems simultaneously to both emphasize and downplay difference. Readers could easily see downplayed example differences as significant.
 
Among the topics around speculation and experimentation I found the bridging concept of calculation particularly important. A calculation is a form of modeling. Hacking referenced many ideas of his own and others about meanings of speculation (theory) and experimentation (observation). However, until he addressed the bridging aspect of calculation in the speculation-calculation-experimentation framework, the two seemed somewhat independent. In fact, many of Hacking’s reference philosophers argued specifically a lack of connection between theory and empirical data.
 
This framework also answered a longstanding question for me. So often in science classes teachers would introduce the idea of constants. These constants were usually attached to the name of a scientist who ‘discovered’ or ‘introduced’ the constant. They never were explained. We were just taught how to incorporate a specific constant into a formula to obtain the answer to a specific scientific process. Hacking explains how a calculation comes about from a need to explain a given observation or experimental data set (artifact, phenomenon). Adding a constant to make a calculation consistently approximate the expected outcome allows science to adopt a theory that adheres to accepted scientific principles. The beauty of such a bridging approach is it also allows for change in both theory and experiment without shifting the calculation. The same calculation can be used to support different theories or outcomes.
 
The resulting approximation becomes yet another central argument Hacking spends considerable time discussing. If a formula and data from empirical observation consistently approximate theoretical prediction, is that bringing us any closer to truth, or just substantiating a theory that purports to stand for truth? Perhaps the substantiation is merely for a given system generally accepted by the larger scientific community at the time of the speculation-calculation-experimentation linkage.