A systematic bias is a bias arising from how participants in some joint process work together. It is related to, and may arise in part from, a systemic bias. However, one deals with the two in quite different ways - while a systemic bias can often be dealt with simply by disrupting the cliques and inviting in new participants and raising awareness, a systematic bias can only be addressed by what is known in legal terms as "due process" - a dragging-out and delaying of decisions so that persistent factual claims can be evaluated, and decisions are not made until a deliberation has occurred on the credibility of each one. This may involve factionalism to a degree and an w:adversarial process in which each faction gets to assert its truth, and where these compete to define reality, but with other factors (such as who holds the actual technological and killing power) equalized. This is of course the function of a courtroom where the term "due process" emerged/applied.
For ordinary distinctions such as, e.g. "simple vandalism" on a large public wiki, such due process may be overkill. However, for deep distinctions that involve the sysop power structure, such as sysop vandalism, there is going to be a "due process" or nothing, since, the sysops themselves have the technological power to prevent their own activities from being investigated.
consequences of systematic bias
The concept of the w:carceral state may be relevant: This was Michel Foucault's generalization of Jeremy Bentham's "Panopticon" or prison-like society where authority could see and control everything, but its own secret investigations and deliberations were entirely invisible to those it controlled. In this world, there is a systematic bias that makes police acts non-transparent, and public acts transparent, thus the police/public distinction determines every other distinction anyone in society can make. This is mirrored pathethically by sysop power structure in most wiki code and on every large public wiki so far - it's probably inevitable.
Groupthink and the echo chamber are the natural result of an unaddressed systematic bias. While a group may have a systemic bias to accepting the outputs of such phenomena as "real", it takes a lack of process and an abdication of publishers' responsibility (see libel pit) for them to accept those outputs as being viable consensus decision-making. Thus only a disciplined notion of such decision making can alleviate the systematic bias.
This is such a serious problem that some very respected thinkers have concluded that only a separation of w:epistemic community by value system can be effective in creating "objective" categories. The most famous examples being the burning of "pagan" texts by Christians, the development by Marxists and some syndicalists of a "working class" specific education system, various social and alternate histories from feminism, and recently and less famously the w:Islamization of knowledge proposed by the Palestinian Ismail al-Faruqi. In all these cases, people sharing a value system would be expected to share ethical principles as well, and those would guide their categorizations - this seems obvious for ethics and law, but is it also true for all facts?
There are over one thousand librarian-created categorization schemes in the largest collections of these. This suggests strongly that there is no single hierarchy of classification of knowledge, and that each means of agreeing on a single hierarchy is probably itself evidence of yet another systematic bias.
It remains however possible to have a good systematic bias, if one has a value system. That is, one can evaluate goodness without much controversy from within a culture, and determine for each proposed change (or "edit" in the case of a wiki) whether it is making the overall body of law/thought/knowledge "better" or "worse".
This is the function of factions - a degree of factionalism is far preferable to cliques and authoritarianism, at least, this is the choice that has actually been made in developed nations, which evolve towards multi-party democracy, and away from GodKing rule.
To evaluate edit quality based on so-called authorship subverts critical evaluation and the function of factions - such subversion is the purpose of the Wikipedia Liars Club and other bureaucracies and cliques that are devoted to negating value systems as such, and simply promoting the power structure that has favoured them so far. This is not surprising: some Jews even joined the German Nazi Party in the 1930s, believing it would exempt them from persecution.
Such delusions are rarely rewarded, as a systemic bias based on identity usually outweighs any amount of effort to impose a favourable systematic bias. That is, no matter how much someone might work to favour "ruling class" or "Aryan" or "white" interests, in the end, if they are not themselves clearly members of this class, the imposition of this power structure will simply not favour them. In the pathetic case of sysop power structure one finds, for instance, females readily engaged in enforcing the edicts of males, thinking this makes them part of a "club". In reality, they are usually/often mocked as dupes by those whose orders they follow, especially if they apply a bias against exactly the measures intended to enable them, e.g. w:feminism.